Chapter 3: Implementation
Chapter 3 Objective 3.1 Insecure Protocols Telnet → Port 23 → Telnet transmits data in plaintext, vulnerable to MITM & Eavesdropping Secure Alternative → SSH → Port 22 → SSH provides encrypted communication FTP → Port 21 → FTP transmits data in plaintext, vulnerable to interception & tampering Secure Alternative → FTPS (FTP Secure) → Port 990 / 989 → Uses SSL / TLS for encryption SFTP (SSH File Transfer Protocol) → Port 22 → Uses SSH for file transfer HTTP → Port 80 → HTTP transmits data in plaintext Secure Alternative → HTTPS → HTTP Secure → Port 443 → Uses SSL / TLS SMTP → Port 25 → SMTP transmits emails in plaintext, vulnerable to interception & unauthorized access Secure Alternative → SMTPS → SMTP Secure → Port 465 → use SSL/TLS to encrypt email communications SMTP with STARTTLS → Port 587 → use SSL/TLS to encrypt email communications POP3 → Port 110 → POP3 transmits emails in plaintext, vulnerable to eavesdropping Secure Alternative → POP3S → POP3 Secure → Port 995 → uses SSL/TLS IMAP → Port 143 → IMAP transmits data in plaintext, vulnerable to interception Secure Alternative → IMAPS (IMAP Secure) → Port 993 → uses SSL / TLS SNMP v1/v2 → Port 161/162 → Lacks encryption, vulnerable to interception & tampering Secure Alternative → SNMPv3 → Port 161/162 → Adds encryption, authentication & integrity protection to data LDAP → Port 389 → LDAP transmits data in plaintext, vulnerable to interception & tampering Secure Alternative → LDAPS (LDAP Secure) → Port 636 → Uses SSL/TLS for encrypt directory service Protocols DNS Security Extensions (DNSSEC) → Provides validation for DNS responses It adds Resource Record Signature (RRSIG) (Digital Signature) to each record RRSIG provides data integrity & authentication for DNS replies Helps to prevent DNS poisoning attack S/MIME → Secure/Multipurpose Internet Mail Extensions Used to digitally sign & encrypt an email Uses both asymmetric & symmetric encryption SRTP → Secure Real Time Protocol → Uses port 5004 RTP → Real Time Protocol → Delivers audio & video over IP networks SRTP provides encryption, message authentication & integrity for RTP LDAPS → LDAP over TLS uses port 636 FTPS → FTP, Secure → uses TLS to encrypt FTP traffic SNMPv3 → Simple Network Management Protocol → Monitors & manages network devices such as routers & switches Uses port 161/162 Can modify devices’ configuration & can check device report status SNMPv3 agents installed on devices send information to SNMP manager via notifications known as traps Flood guard sends SNMP trap messages in response to an alert SNMP Usage → Commonly used to gather information from routers, switches, and other network devices → It provides information about a device’s status, including CPU and memory utilization, as well as many other useful details about the device IPSec → Used to encrypt IP traffic Authentication Header → IPSec uses AH to allow each conversation hosts to authenticate with each other before exchanging the data AH provides authentication & integrity Encryption → IPSec includes Encapsulating Security Payload (ESP) to encrypt data & provide confidentiality IPSec uses Internet Key Exchange (IKE) to authenticate clients in the IPSec conversation → Internet key exchange (IKE) is used to set up security associations (SAs) on each end of the tunnel. Modes: Transport Mode → Only the payload (the data being transmitted) of the IP packet is encrypted and/or authenticated. The IP header remains intact. Typically used for end-to-end communication between two hosts or devices. Tunnel Mode → The entire IP packet (including the original IP header and payload) is encapsulated within a new IP packet with a new IP header Commonly used for site-to-site VPN connections where entire packets need to be protected. Post Office Protocol (POP3) → Transfers emails from servers down to clients POP3 → Port 110 POP3S → Port 995 IMAP → Internet Message Access Protocol → Used to store email on the server & it allows users to organize & manage emails in folders on the server IMAP → Port 143 IMAP Secure → Port 993 Use Cases Voice and video → Real Time Protocol (RTP) → a network protocol designed for delivering audio and video over IP networks Secure Real Time Protocol (SRTP) → An extension of RTP that provides encryption, message authentication, and integrity, as well as replay protection for RTP data. SRTP ensures secure transmission of real-time audio and video communications. Session Initiation Protocol (SIP) → A signaling protocol used to initiate, maintain, modify, and terminate real-time sessions that involve video, voice, messaging, and other communications applications and services. Time Synchronization → Network Time Protocol (NTP) → A protocol used to synchronize the clocks of computers over a network. Simple Network Time Protocol (SNTP) → A simplified version of NTP, used for less complex and less demanding synchronization needs It provides time synchronization but with reduced accuracy and fewer features compared to NTP. Email and Web → Simple Mail Transfer Protocol (SMTP), Post Office Protocol (POP), Internet Message Access Protocol (IMAP), HTTP, HTTPS File Transfer → File Transfer Protocol (FTP), Trivial File Transfer Protocol (TFTP), SSH, SSL, TLS, IPSec, SFTP, FTPS Directory Services → LDAP Remote Access → Remote Desktop Protocol (RDP) → Uses port 3389 Domain Name Resolution → DNSSEC Network Address Allocation → IPv4, IPv6 Objective 3.2 Endpoint Protection Endpoint Detection & Response (EDR) → Provides continuous monitoring of endpoints Performs a deep investigation of all activity on endpoints Collect and analyze data from endpoints to detect anomalies, provide visibility into potential threats, and facilitate timely responses to incidents. Incident response, threat hunting, forensic analysis Data Loss Prevention (DLP) → Prevent data loss Next-Generation Firewall (NGFW) → An advanced firewall that adds capabilities that aren’t available in first generation or second generation firewalls NGFW performs deep packet inspection, adding application level inspection as a core feature NGFW can identify application commands & detect potentially malicious traffic Features → Deep Packet Inspection (DPI), Integrated IPS, Identifies and controls applications, Sandboxing, malware detection, SSL/TLS decryption, Built-in URL filtering Comparison First Gen → Packet Filtering → Based on IP addresses, ports, and protocols Second Gen → Stateful Packet Inspection → Tracks active connections and the state of the connection NGFW → Deep Packet Inspection (DPI) → Identifies applications, users, and content HIDS → Host-Based Intrusion Detection System An additional software installed on a system such as workstation or a server For HIDS, the traffic passes through the network interface card (NIC) HIDS can help to detect malicious software (malware) that traditional antivirus can miss Boot Integrity UEFI → Unified Extensible Firmware Interface → Performs many of same functions as BIOS but provides some enhancement A specification for a software program that connects a computer’s firmware to its operating system (OS) BIOS → provides instructions on starting → It runs some basic checks, locates the OS & boots BIOS & UEFI can be upgraded with using flashing → Flashing overwrites the software within the chip with newer software BIOS vs UEFI BIOS → Initializes hardware components and boots the OS Generally slower boot times due to the sequential initialization process. UEFI → More complex initialization process with support for modern hardware and boot methods Faster boot times due to parallel initialization processes and optimized boot methods Measured Boot → Goes through enough boot process to perform these checks without allowing a user to interact with a system. If it detects that system has lost integrity & can no longer be trusted, the system won’t boot A security feature that helps ensure the integrity of the boot process by recording each step in the boot sequence and storing the measurements in a secure location, typically in a Trusted Platform Module (TPM) Boot Attestation → Signature Key Files used to boot the computer Boot attestation requires that systems record and measure the boot process, and subsequently verify to a system that the process was secure. Measured Boot Vs Secure Boot Measured Boot → Ensure integrity of the boot process through measurements Records and stores measurements of each boot component in TPM Can provide remote attestation of system integrity Useful for environments requiring verifiable integrity Secure Boot → Ensure only trusted code is executed during boot Verifies digital signatures of each boot component Does not provide remote attestation Useful for environments requiring strict execution control Trusted Boot → Verifies the operating system kernel signature and starts the ELAM(Early Launch Anti-Malware) process. Cryptographically verifies each boot stage Verifies each stage using digital signatures Integrity and authenticity of entire boot process Devices requiring complete boot process security Database Tokenization → Replaces sensitive elements with a token A tokenization can convert the token back into its original form Salting → Adds random texts to passwords before hashing them Used to prevent rainbow table attacks, brute force & dictionary attack Application Security Secure Cookies → Cookie that has the secure attribute set When a cookie has the Secure attribute, the user agent includes the cookie in an HTTP request only if the request is transmitted over a secure channel (typically HTTPS). Code Signing → Identifies author & the hash verifies that code hasn’t modified Verifies the originator of the component & thus make malware less likely SED & FDE Full Disk Encryption (FDE) → Encrypts the entire disk Users typically need to enter a password or use a cryptographic key stored on a separate device (like a smart card or USB token) to unlock the disk and access its contents. Ex. Veracrypt, BitLocker (Windows), FileVault (macOS), LUKS (Linux). Self Encrypting Drive (SED) → Also known as hardware based FDE drives Automatically encrypts & decrypts data on a drive without user interaction A storage device that automatically encrypts data before it is written to the drive and decrypts it when read, without requiring any action from the operating system or user. SED doesn’t need authentication Opal → Set of specifications for SEDs It defines what hardware vendors must do to ensure SEDs are configured to prevent unauthorized access Opal-Compliant drives requires users to enter credentials to unlock the drive while booting the system Trusted Platform Module TPM is hardware chip on computer’s motherboard that stores cryptographic keys used for encryption TPM provides Full Disk Encryption capabilities It keeps the hard drives locked or sealed until the system completes the system verification & authentication process TPM supports boot attestation process → When TPM is configured, it captures signature of key files used to boot the computer & stores the report of signatures within the TPM Uses burned-in cryptographic keys & Includes built-in protections against brute-force attacks Secure Boot → When system boots, the secure boot process checks the files against the stored signatures to ensure that they haven’t changed → If it detects that files have been modified, it blocks the boot process to protect the data on the drive Remote Attestation → It uses a separate system instead of checking boot files reports in TPM It captures the signatures of key files & sends it to remote system Hardware root of trust → When private key matched with the public key, it provides hardware root of trust also known as Known Secure Starting Point A TPM includes a unique RSA asymmetric key burned into the chip that provides a hardware root of trust Objective 3.3 Load Balancing Active/Active → Can optimize & distribute data loads across multiple computers / networks Distributes traffic equally among all the servers in the web farm Scheduling → Load balancers use a scheduling technique to determine where to send a new request. They use Round-Robin algorithm to send request Persistence → Load balancers use source address affinity to direct the request Source affinity sends requests to the same server based on the requester’s IP address & provides the user with persistence Load balancers can detect when a server fails → If server stops responding, load balancers will not send request to this server → Contributes to high availability Active/Passive → One server is active & another server is inactive If active server fails, the inactive server takes over Two servers have a monitoring connection to each other to check each other’s health Load Balancer Algorithms Least connection-based → takes load into consideration and sends the next request to the server with the least number of active sessions Round Robin → simply distributes requests to each server in order Weighted Time → Uses health checks to determine which server is currently responding the quickest, and routing traffic to that server. Source IP Hash → Uses a unique hash key generated from the source and destination IP addresses to track sessions, ensuring that interrupted sessions can be seamlessly reassigned to the same server, thus allowing the sessions to continue uninterrupted. Network segmentation Virtual Local Area Networks (VLAN) → Separates or Segments traffic on physical networks A logical network segment within a physical network infrastructure that allows devices to be grouped together even if they are not physically connected on the same network switch. We can create multiple VLANs with a single Layer 3 Switch A VLAN can locally group several computers together or logically separate computers without regard their physical location VLANs are used to separate various traffic types (voice, data) Screened Subnet → Buffer zone between internet & intranet (internal network) It allows to access services while segmenting access to internal network An additional layer of security is implemented to protect internal networks from external threats East-West → Refers to traffic between servers Intranet → Internal Network Extranet → Part of the network that can be accessed by authorized entities from outside of network Zero Trust → A network that doesn’t trust any devices by default, even if it’s previously verified Helps to reduce attacks from internal clients Zero trust in not technology, instead it is a security model based on principle of zero trust VPN SSL/TLS → Some tunneling protocols use TLS to secure VPN channels Provides the easiest way for users to use VPN since it does not require a client. (most user-friendly) Split Tunnel → A VPN admin determines what traffic should use the encrypted tunnel Full Tunnel → All traffic goes through the encrypted tunnel while the use is connected to VPN Site-to-Site VPN → Includes two VPN servers that acts as a gateways for two networks separated geographically IPSec VPNs are used for site-to-site VPNs Ex. Users in the remote office can connect to the servers in the HQ location easily Always-On → Create a VPN connection as soon as user’s device connect to the internet Layer 2 tunneling protocol (L2TP) → L2TP is tunneling protocol → Uses port 1701 Uses IPsec for encryption, providing confidentiality and integrity of data transmission. Combines the features of PPTP (Point-to-Point Tunneling Protocol) and L2F (Layer 2 Forwarding) to create a tunnel between two endpoints. HTML5 VPN Portal → Allows users to connect to the VPN using their web browser It uses TLS to encrypt the session → Can be resource intensive SSTP → Secure Socket Tunneling Protocol A VPN protocol developed by Microsoft for creating secure, encrypted connections over the internet SSTP is designed to provide secure remote access to networks by tunneling Point-to-Point Protocol (PPP) traffic through an SSL/TLS channel. → Port 443 TCP Network access control (NAC) Refers to a set of technologies and policies used by organizations to ensure that devices connecting to their networks are secure and compliant with established security policies Features: Verifies the identity of users and devices attempting to connect to the network. Checks endpoints (devices) for compliance with security policies and configurations before granting network access. Defines rules and policies that dictate who and what can access specific parts of the network. Automatically corrects or isolates non-compliant devices to remediate security issues before allowing access. Monitors connected devices continuously to detect anomalies or suspicious behavior. Integrates with existing security solutions such as firewalls, IPS/IDS, SIEM Helps organizations improve network security by controlling access, enforcing policies, and detecting/responding to security threats in real-time. Agent NAC → NAC uses agent when the client attempts to log on remotely A permanent agent installed on the client & stays on client Agentless NAC → A dissolvable agent is downloaded & runs on client when clients logs on remotely It collect the information it needs, identifies the client as healthy or non-healthy & reports the status back to NAC system NAC agents remove themselves immediately after they report to the NAC system Other NAC agents remove themselves after session ends An agentless NAC system scans a client remotely without installing code on the client Port Security Port security limits the computers that can connect to physical ports on a switch MAC Filtering → Restricts access to switch ports based on the MAC (Media Access Control) address of devices connected to the port. Ex. Each physical port is assigned to a single specific MAC address → MAC Address Sticky Port security filters by MAC address, allowing whitelisted MAC addresses to connect to the port and blocking blacklisted MAC addresses. Broadcast Storm → Caused when two ports of a switch connected together Spanning Tree Protocol (STP) & Rapid STP (RSTP) helps to prevent broadcast storm & loop prevention for switches BPDU Guard → Bridge Protocol Data Unit Guard STP sends BPDU in the network to detect loops When the loops are detected, STP blocks the traffic from switch ports sending redundant traffic DHCP Snooping → DHCP snooping is a preventive measure When DHCP snooping is enabled, the switch only send DHCP broadcast traffic (DHCP Discover Message) to trusted ports Prevents rogue DHCP servers as well as malicious or malformed DHCP traffic. It also allows the capture and collection of DHCP binding information to let network administrators know who is assigned what IP address. Network Appliances Jump Servers → Also called Jump box → A hardened server used to access & manage devices in another network with a different security zone A jump server is places between different security zones It can provide secure access to devices in screened subnet from internal network Proxy Servers → Forwards requests from clients for services like HTTP or HTTPS → Forward Proxy Server Improves performance by caching content Can restrict users’ access to inappropriate websites by filtering content A proxy server is located on the edge of the network bordering the internet & intranet A web proxy can be used to block certain websites. Transparent Proxy → Accepts & forwards requests without modifying them Non-Transparent Proxy → Use URL filters to restrict access to certain sites Both types of proxy log user activity Reverse Proxy Server → Accepts requests from internet for a single web server It appears as a web server to clients but it forwards requests to the web server & serves pages returned by web server Reverse proxy is configured to protect the web server Reverse proxy server can be used for a web farm of multiple servers → When it is used with web farm → It can act as a load balancer Forward Proxy Vs Reverse Proxy Forward Proxy → A forward proxy regulates client access to the internet, enhancing security and policy enforcement within an internal network It sits between the client and the internet and forwards client requests to the internet. In a corporate network, a forward proxy may be used to control access to the internet and enforce security policies. Reverse Proxy → A reverse proxy, manages external requests to servers, offering load balancing and concealing server identities for added security It sits in front of servers and directs client requests to the appropriate backend servers. A reverse proxy can distribute incoming web requests to multiple web servers in a server farm. NIDS / NIPS Signature-based Detection → Detects known malware based on signature definitions Heuristic-Based Detection → Detects previously unknown malware based on behavior Can detects unknown anamalies Inline → An IPS placed inline with traffic can detect, react to & prevent attacks Passive → Collects data passively Heuristic vs Anomaly-based detection Heuristic: Heuristic IPS uses algorithms and rules to detect potentially malicious behavior, often identifying new and unknown threats. However, it does not specifically create a baseline of normal activity. Heuristic IPS technology uses artificial intelligence to identify attacks that have no prior signature. Anomaly-based: Anomaly-based IPS establishes a baseline of normal network behavior and then monitors traffic to detect and block deviations from this baseline. This makes it the best fit for the requirement of observing normal network activity and blocking deviations Hardware Security Module (HSM) → A security device that can added to a system to manage, generate & securely store cryptographic keys HSM supports security methods of TPM Many server based applications use an HSM to protect keys Aggregators → Store log entries from dissimilar systems Firewalls Stateful → Inspects traffic & makes decisions based on the traffic context or state Unified Threat Management (UTM) → A single solution that combines multiple security controls UTM will reduce the workloads of admins without sacrificing security URL Filtering → Performs same job as a proxy server → Block access to sites based on the URL Admins can configure URL filters to allow / block access to specific sites Malware Inspection → Screens incoming data for known malware & blocks it Content Inspection → Monitors incoming data streams & attempts to block any malicious content Includes spam filter to inspect incoming emails Can block specific type of transmissions such as audio or video & file types such as .zip DDOS Mitigator → Attempts to detect DDOS attacks & blocks them Common security issue of UTM is misconfigured content filter Key Features → Firewall, IPS/IDS, Antivirus & Anti-malware, Content Filtering, Spam Filtering, Application Control, Web Filtering, DLP, Logging, Reporting Network Address Translation (NAT) Gateway → NAT is a protocol that translates public IP addresses to private IP addresses & private addresses back to public. NAT gateway hosts NAT & provides internal clients with private IP addresses a path to internet Benefits: Public IP addresses don’t need to be purchased for all clients NAT hides internal computers from the internet Hides the internal network structure, making it harder for attackers to target specific devices. Static NAT → Uses single public IP address in one-to-one mapping Dynamic NAT → Uses multiple public IP addresses in one-to-many mapping Quality of service (QoS) → Refers to technologies running on a network that measure & control different traffic types It allows admins to prioritize certain types of traffic over others Implications of IPv6 → All devices on internal network don’t support IPv6 natively Port Mirroring → Port Spanning → Port Tap → Allows admins to configure the switch to send all traffic the switch receives to a single port Port Mirroring is not passive (active) Network Tap → Network taps copy all traffic to another destination, allowing traffic visibility without a device inline. Network tapping is completely passive File Integrity Monitor (FIM) → Some antivirus scanners use file integrity monitors to detect modified system files by calculating hash of systems files as a baseline Objective 3.4 Cryptographic Protocols WEP → RC4 stream cipher → 64-bit or 128-bit Vulnerable to various attacks (e.g., IV attacks, dictionary attacks) WiFi Protected Access (WPA) → Introduced to address the weaknesses of WEP. Introduced to address the weaknesses of WEP. TKIP (Temporal Key Integrity Protocol) Uses 802.1X for enterprise or PSK (Pre-Shared Key) for home networks WiFi Protected Access 2 (WPA2) → WPA2 can operate in open, enterprise or Pre-Shared key (PSK) mode Utilizes Advanced Encryption Standard (AES) for encryption Supports both 802.1X (EAP) and PSK authentication methods. Open Mode → Doesn’t use any security → All data transferred in cleartext PSK or Enterprise Mode → Users access the wireless network anonymously with a PSK or passphrase Enterprise mode forces users to authenticate with unique credentials before granting them access to the wireless network Enterprise mode uses 802.1X server, often implemented as RADIUS server (Authentication) WiFi Protected Access 3 (WPA3) → Newest wireless cryptographic protocol It uses Simultaneous Authentication of Equals (SAE) instead of PSK used with WPA2 SAE is a variant of Dragonfly Key Exchange which is based on Diffe-Hellman A password-based authentication and key exchange protocol used primarily in wireless networks WPA3 is replacement for WPA2 WPA3 also supports enterprise mode → Uses RADIUS server & requires users to authenticate SAE helps to prevent brute-force attacks against keys by making attackers interact with the network before each authentication attempt. This slows down brute-force attacks. Comparison → WPA3 > WPA2 > WPA > WEP Counter-mode/CBC-MAC Protocol (CCMP) → WPA2 uses strong cryptographic protocols such as AES & Counter Mode/CBC-MAC Protocol (CCMP) An encryption protocol used in WiFi networks to provide confidentiality, integrity & authentication. Simultaneous Authentication of Equals (SAE) → WPA3 uses SAE instead of PSK Authentication Protocols Extensible Authentication Protocol (EAP) → EAP provides method for two systems to create a secure encryption key also known as Pairwise Master Key Systems use this key to encrypt all data transmitted in between the devices AES based CCMP uses this key Used with WPA-Enterprise or WPA2-Enterprise. Lightweight EAP (LEAP) → LEAP is an early EAP method developed by Cisco Systems Uses a variant of MS-CHAP (Microsoft Challenge-Handshake Authentication Protocol) for authentication. Deprecated due to security vulnerabilities. Protected EAP (PEAP) → Provides an extra layer of protection for EAP PEAP protects the communication channel by encapsulating & encrypting the EAP conversation in TLS tunnel PEAP requires a certificate on the server but not on the client Ex. Microsoft Challenge Handshake Authentication Protocol version 2 (MS-CHAPv2) Used in enterprise Wi-Fi networks with server-side certificates. EAP-FAST → EAP - Flexible Authentication via Secure Tunneling → Replacement for lightweight EAP (LEAP) EAP fast supports certificates, but they’re optional Uses a Protected Access Credential (PAC) to establish a TLS tunnel between the client and the authentication server. Provides mutual authentication and protection against man-in-the-middle attacks. Used in environments requiring lightweight and secure authentication. EAP-TLS → EAP-TLS requires certificates on the 802.1X server & clients EAP-TLS is an EAP method that uses TLS for mutual authentication between the client and the server. Used in environments requiring strong mutual authentication and encryption. EAP-TTLS → EAP-TTLS is an extension of PEAP EAP-TTLS is an EAP method that encapsulates EAP methods within a TLS tunnel. Allows systems to use older authentication methods such as password authentication protocol (PAP) within a TLS tunnel Used in environments where user credentials are stored centrally. RADIUS Federation → Creates a federation using 802.1X & RADIUS servers Methods WiFi Protected Setup (WPS) → Allows users to configure wireless devices without typing in the passphrase Users can configure devices by pressing buttons or by entering a short eight-digit PIN WPS is susceptible to brute force attacks Captive portals → A technical solution that forces clients using web browsers to complete a specific process before it allows them to the network Free internet access, paid internet access Alternative to 802.1X, as 802.1X can be expensive & sometimes not feasible to organizations Installation Considerations Site Survey → Examines the wireless environment to identify potential issues, such as areas with noise or other devices operating on the same frequency bands Admins can periodically perform site survey to verify that environment hasn’t changed & detect potential security issues Heat Maps → Gives you a color-coded representation of wireless signals Color red shows where the wireless signals are strongest Color blue shows where the wireless signals are weakest Also it shows dead spots WiFi Analyzers → Identifies activity on channels within the wireless spectrum & analyze activity in 2.4 & 5 GHz frequency ranges Allows you to analyze one frequency range at a time & see each channel’s activity on a graph BSSID → Basic Service Set Identifier → Unique identifier used in 802.11 WiFi networks to identify a specific access point within a Basic Service Set (BSS) Objective 3.5 Mobile Device Management (MDM) Vendors sell Unified Endpoint Management (UEM) solutions to manage mobile devices Application Management → Can restrict what applications can run on mobile devices Use allow list to control applications & prevent unapproved application from installing Full Device Encryption → Organizations use full device encryption on corporate-devices to provide device security, application & data security Storage Segmentation → Used to isolate data Users might required to use external storage for any corporate data to reduce the risk of data loss if device is lost Content Management → Can force user to authenticate again when accessing data within the encrypted segment Containerization → Organizations can encrypt a container in mobile devices without encrypting the entire device Running organization application in container isolates & protects the application & data Useful when employees use their own device Geolocation → Includes GPS capabilities to identify the location of the device & device movement Geofencing → Organization use GPS to create a virtual fence or geographical boundary GPS Tagging → Adds geographical information to the files such as pictures when posting them on social media Context-Aware Authentication → Uses multiple elements to authenticate a user & mobile device It can include user’s identity, geolocation & verification that the device is within a geofence, time of day & type of device These elements help prevent unauthorized users from accessing the app & data SEAndroid → Security-Enhanced Android (SEAndroid) uses Security-Enhanced Linux (SELinux) to enforce access security It operates using default denial principle → Anything not allowed is denied Enforces Mandatory Access Control (MAC) SELinux supports two modes: Enforcing Mode → This mode enforces SELinux policy. Any activity that is denied by the policy is blocked & logged Permissive Mode → This mode doesn’t enforce SELinux Policy but it does log all activity that policy would block if it was in enforce mode Admins use this mode to verify that policy works as intended before changing it to enforcing mode Enforcement and Monitoring Jailbreaking → Refers to removing all software restrictions from Apple Devices Rooting → Process of modifying an Android device to give the user a root level access to device Sideloading → Process of copying apk to the device & then activating / installing it Over-The-Air (OTA) Updates → Updates to the OS overwrites the firmware using OTA updates ad hoc → In ad hoc mode, wireless devices connect to each other without access point Objective 3.6 Solutions Cloud Access Security Broker (CASB) → A software tool or service deployed between an organization’s network & the cloud provider It provides security by monitoring traffic & enforcing security policies Functions: Visibility → Identifies and monitors cloud applications, data flows, and user activities. Data Security → Protects data through DLP, encryption, tokenization, and access controls. Threat Protection → Detects and blocks malware, identifies anomalies, and integrates threat intelligence. Compliance → Enforces regulatory policies, provides audit trails, and supports legal holds. IAM → Integrates SSO, MFA, and automates user provisioning and deprovisioning. Shadow IT Control → Discovers, assesses, and mitigates risks associated with unauthorized cloud services. Security Configuration → Manages and monitors cloud service configurations to ensure compliance with security policies. Collaborating & Sharing Control → Controls and monitors data sharing and collaboration within cloud platforms. Next Generation Secure Web Gateway (SWG) → A combination of proxy server & stateless firewall Clients are configured to access all internet resources via the SWG & it filters the traffic to prevent threats from infiltrating the network SWG Includes: URL filtering → prevent users from visiting unauthorized sites Stateless Packet Filtering → To detect & block malicious traffic Malware detection & filtering to block malware Network-based Data Loss Prevention (DLP) Sandboxing to check for threats Objective 3.7 Identity Identity provider (IdP) → Creates, maintains & manages identity information for principles Account Types Personal or End-User Account → Admins create these accounts & assign appropriate privileges based on user’s responsibilities Basic credential policy Administrator & Root Accounts → Privileges accounts that have additional rights & privileges beyond what regular user has Credential policy requires stronger authentication such as MFA Service Accounts → Some application & services need to run under the context of account Admins create a regular user account for service like SQL, provide appropriate privileges & configure a SQL server to this account This account is like a regular user account but the difference is it is used by service or application not by user Credential policies may require long, complex passwords for this accounts & passwords should not expire It is common practice to prohibit interactive logins to a GUI or shell for service accounts. Use of a service account for interactive logins or attempting to log in as one should be immediately flagged and alerted on as an indicator of compromise (IoC). Device Accounts → Computers & other devices also have accounts Ex. Microsoft Active Directory only allows users to log on to computers joined to the domain Third-party Accounts → Accounts from external entities that have access to the network Strong Credential Policy Guest Accounts → Useful if you want to grant someone limited access to compute or network without creating a new account Admins commonly disable guest accounts & only enable it in special situations Sponsored Authentication for Guest Accounts → Requires a guest user to provide valid identification when registering their wireless device for use on the network. This requires that an employee validates the guest’s need for access, which is known as sponsoring the guest. Shared / Generic Account / Credentials → Organizations create a regular user account that temporary workers will share. If a temporary agency sending a different person everyday, a shared account may provide better solution than guest account because the access can be tailored for the shared account Basic credential policy Account Policies Time-based Logins → Referred as time of the restrictions → Ensure that users can only log on to computers during specific times Objective 3.8 Authentication Management Knowledge-based authentication → Organization use KBA to prove the identity of individuals Static KBA → Used to verify the identity when you’ve forgotten your password Ex. Your first dog’s name Dynamic KBA → identifies individuals without account Organizations use this for high risk transactions such as financial institutions or healthcare industry The site queries public & private data source such as credit reports It craft MCQ questions that only the user would know & users typically have limited amount of time to answer these questions → This limits the amount of time an attacker can do searches on the Internet to identify accurate answers Cognitive password attack → A form of knowledge-based authentication that requires a user to answer a question, presumably something they intrinsically know, to verify their identity. If you post a lot of personal information about yourself online, then this type of password can easily be bypassed. Authentication / Authorization Password Authentication Protocol (PAP) → Used with Point-To-Point protocol (PPP) to authenticate clients A significant weakness of PPP is that it sends passwords over network in cleartext Susceptible to sniffing attacks Challenge-Handshake Authentication Protocol (CHAP) → Uses PPP & authenticates remote users, but it is more secure than PAP The goal of CHAP is to allow the client to pass credentials over a public network without allowing attackers to intercept the data & later use it in attack CHAP uses an encrypted challenge & three-way handshake to send credentials Prevents session hijacking RADIUS → Remote Authentication Dial-In Service → Centralized Authentication Service It is a networking protocol used for centralized authentication, authorization, and accounting (AAA) management in computer networks. RADIUS servers are commonly used to authenticate users accessing network resources, such as Wi-Fi networks, VPNs, and other network services. Uses port 1812 / 1813 Instead of each VPN server needing a separate database to identify & authenticate, VPN servers forwards the authentication requests to central RADIUS server RADIUS can be also used with 802.1X server with WPA2 Enterprise Mode Each VPN server is configured with a shared secret & the RADIUS server is configured with the matching shared secret for each of the VPN servers Centralized RADIUS servers holds a centralized database of user accounts → LDAP Server RADIUS uses UDP which provides best delivery mechanism RADIUS only encrypts password by default & can be used with EAP to encrypt the entire session TACACS+ → Terminal Access Controller Access-Control System Plus → RADIUS alternative Uses port 49 Uses TCP to provide Authentication, Authorization & Accounting services It provides two essential security benefits over RADIUS It encrypts the entire authentication process It uses multiple challenges & responses between the client & server It is authentication service for network devices & it can be used with Kerberos SAML → Security Assertion Markup Language → an XML based format used for SSO on web browsers If organization trust each other, they can use SAML as a federated identity management system Users authenticate with one website & are not required to authenticate again when accessing the second website Many web based portal use SAML for SSO SAML defines three roles: Principal → Principal is typically a user → User log once & if necessary, principal requests an identity from identity provider Identity Provider (IdP) → Creates, maintains & manages identity information for principals Service Provider → An entity that provides services to principals Kerberos → A network authentication protocol used within Windows Active Directory domains & some unix environments known as realms It provides mutual authentication that can help to prevent on-path attacks & uses tickets to prevent replay attacks Uses port 88 Kerberos includes several requirement to work properly: A method of issuing tickets used for authentication: A key distribution center uses a complex process of issuing ticket-granting tickets (TGTs) & other tickets Tickets provide authentication for users when they access resource such as files on the file server These tickets sometimes referred as tokens Time Synchronization → Kerberos v5 requires all systems to be synchronized within 5 minutes of each other Helps to prevent replay attacks A database of subjects or users → DB of users When users log on to Kerberos, KDC issues a ticket to the user, typically with a lifetime of 10 hours to be useful for single workday When users try to access resource, they present ticket for authentication & user is issues a ticket to access the resource Kerberos uses symmetric key cryptography to prevent unauthorized disclosure & to ensure confidentiality Kerberos does not send the users password across the network. → When the user’s name is sent to the authentication service, the service retrieves the hash of the user’s password from the database → then uses that as a key to encrypt data to be sent back to the user. → The user’s machine takes the password that the user entered, hashes it, and then uses that as a key to decrypt what was sent back by the server. Access Control Schemes Attribute-based Access Control (ABAC) → Evaluates attributes & grants access based on the value of those attributes Attributes can be characteristics of user, the environment & the resource ABAC uses policies to evaluate attributes & grants access when the system detects a match in the policy Ex. Homer is nuclear safety inspector → Attributes → employee, inspector, nuclear aware Many Software Defined Networks (SDNs) use ABAC schemes ABAC policy statements typically include 4 elements: Subject → Typically a user Object → Resource such as file, database or application Action → Action is what user is attempting to do such as reading or modifying file Environment → Includes everything outside of subject & object attributes ABAC system has a lot of flexibility & can enforce both MAC & DAC scheme Role-based Access Control (RBAC) → Uses roles to manage rights & permissions for users Useful for users within a specific department who perform same job functions Admins create roles & assigns specific rights & permissions to the roles Role-based Access Control is also called hierarchy-based or job-based A matrix is planning document that matches the roles with the required privileges Group-based Privileges → Reduce the administrative workload of access management Admins put user accounts into security groups & assign privileges to the group Users within the group automatically inherit the privileges assigned to the group Rule-based Access Control (Rule-BAC) → Uses rules → Ex. Firewalls / Routers Routers & Firewalls use rules within access control lists (ACLs) It is based on set of approved instructions such as ACL Some Rule-BAC uses rules that trigger in response to an event, such as modifying ACL after detecting an attack or granting additional permissions to a user in a certain situations Mandatory Access Control (MAC) → Uses labels (sometimes referred as sensitivity labels or security labels) to determine access Security admins assign labels to both subjects (users) & objects (files / folders) When the labels match, the system can grant access to subject for the object It is commonly used when access needs to be restricted based on need to know Security labels often reflect classification levels of data & clearances granted to individuals Discretionary Access Control (DAC) → In DAC, objects have an owner & owner establishes access for the objects Many operating systems such as Windows & Unix-based systems use DAC scheme Ex. New Technology File System (NTFS) → Provides security by allowing users & admins to restrict access to files & folders with permissions DAC scheme is more flexible than MAC scheme Conditional Access → Conditional Access policies use signals, which are similar to attributes in ABAC scheme Some common signals are: User / Group membership, IP Location, Device Privileged Access Management (PAM) → Allows an organization to apply more stringent security controls over accounts with elevated privileges such as admin / root account PAM implements the concept of just in-time administration → Admins won’t have administrative privileges until they need them → When they need them, they send a request for the elevated privileges PAM system grant the request, typically by adding the account to a group with elevated privileges After a pre-set time (such as 15 minutes), their account is automatically removed from the group, revoking the privileges PAM Capabilities: Allows users to access the privileged account without knowing the password Automatically change privileges account passwords periodically Limit the time users can use the privileged account Allow users to check out credentials Log all access of credentials It reduces opportunities for attackers to user administrative privileges Filesystem Permissions → NTFS Permissions: Write Read Read & Execute Modify Full Control Objective 3.9 Public Key Infrastructure (PKI) Key Management → Manage public & private keys within PKI Certificate Authority (CA) → Issues, manages, validates & revokes certificates Intermediate CA → Root CA issues certificates to Intermediate CAs & Intermediate CAs issues certificates to child CAs → Child CAs issues certificates to devices or end users Registration Authority (RA) → Assists the CA by collecting registration information RA never issues certificates, instead it only assist in registration process The registration authority works with the certificate authority to identify and authenticate the certificate requester. Certificate Revocation List (CRL) → CAs use CRL to revoke certificates CRL is version 2 certificate that includes a list of revoked certificates identified by their serial numbers Since public keys are distributed via certificates, adding certificate in CRL is best way to deauthorize a public key Certificate Elements: Serial Number → Uniquely identifies the certificate Issuer → Identifies the CAs that issued the certificate Validity Dates → Includes “Valid From” & “Valid To” dates Subject → Identifies the owner of the certificate Public Key → Asymmetric encryption uses the public key in combination with the matching private key Usage → Some certificates are only for encryption or authentication Certificates Attributes: CN → Common Name → fully qualified domain name (FQDN) o → Organization L → Locality S → State or Province C → Country Online Certificate Status Protocol (OCSP) → Allows client to query the CA with the serial number of the certificate to determine if it is valid Indicates if certificate is good, revoked or unknown OCSP is a protocol used by the browser to check the revocation status of a certificate DV (Domain Validation) Certificate → CA verifies that the certificate subject has control of the domain name EV (Extended Validation) Certificate → prove that the X.509 certificate has been issued to the correct legal entity. Certificate Signing Request (CSR) → Used to request a certificate The certificate signing request is sent with the public key to the certificate authority Once the certificate information has been verified, the CA will digitally sign the public key certificate. Subject Alternative Name (SAN) → SAN certificate is used for multiple domains that have different names but are owned by the same organization → Ex. x.google.com, x.android.com Certificate Formats Distinguished Encoding Rules (DER) → Canonical Encoding Rules (CER) & DER are the best formats of certificates CER → Used for ASCII certificates DER → Used for binary certificates PEM → Privacy Enhanced Mail (PEM) → Can be used for any certificate purpose → Most Commonly Used Certificate Format P7B → Use PKCS version 7 format & they are CER-based Used to share public keys with proof of identity of the certificate holder P12 → Use PKCS version 12 format & they are DER based Commonly used to store private key with a certificate Personal Information Exchange (PFX) → Predecessor to the P12 certificate & it has same usage Binary Format Admins use this format on Windows Systems to import or export certificates Concepts Online Versus Offline CAs → Online CA → Accessible over network Offline CA only accept CSR manually Large organizations keep root CA offline to reduce the risk of compromise Stapling → Alternative of OCSP The certificate presenter appends the certificate with a timestamped digitally signed OCSP response from the CA This reduces OCSP traffic to & from the CA Allows client to validate the certificate without contacting the OSCP server Pinning → Helps to prevent attackers from impersonating a web site with a fraudulent certificate The web server sends a list of public key hashes that clients can use to validate certificates sent to clients in subsequent sessions Trust Model → CAs are trusted by placing a copy of their root certificate into a trusted root CA store Key Escrow → The process of placing a copy of a private key in a safe environment If the original key is lost, the organization retrieves the copy of the key to access the data Certificate Chaining → Combines all certificates from the root CA down to the certificate issued to end user