T1195: Supply Chain Compromise

Vulnerability scanning involves the automated or manual assessment of systems, applications, and networks to identify misconfigurations, unpatched software, or other security weaknesses. The process helps prioritize remediation efforts by classifying vulnerabilities based on risk and impact, reducing the likelihood of exploitation by adversaries. This mitigation can be implemented through the following measures:

Proactive Identification of Vulnerabilities

- Implementation: Use tools like Nessus or OpenVAS to scan endpoints, servers, and applications for missing patches and configuration issues. Schedule regular scans to ensure timely identification of vulnerabilities introduced by new deployments or updates. - Use Case: A scan identifies unpatched software, such as outdated Apache servers, which could be exploited via CVE-XXXX-XXXX. The server is promptly patched, mitigating the risk.

Cloud Environment Scanning

- Implementation: Use cloud-specific vulnerability management tools like AWS Inspector, Azure Security Center, or GCP Security Command Center to identify issues like open S3 buckets or overly permissive IAM roles. - Use Case: The scan detects a misconfigured S3 bucket with public read access, which is remediated to prevent potential data leakage.

Network Device Scanning

- Implementation: Use tools to scan network devices for vulnerabilities, such as weak SNMP strings or outdated firmware. Correlate scan results with vendor advisories to prioritize updates. - Use Case: Scanning detects a router running outdated firmware vulnerable to CVE-XXXX-YYYY. The firmware is updated to a secure version.

Web Application Scanning

- Implementation: Use dynamic application security testing (DAST) tools such as OWASP ZAP or Burp Suite to scan for common vulnerabilities like SQL injection or cross-site scripting (XSS). Perform regular scans post-deployment to identify newly introduced vulnerabilities. - Use Case: A scan identifies a cross-site scripting vulnerability in a form input field, which is promptly remediated by developers.

Prioritizing Vulnerabilities

- Implementation: Use vulnerability scoring frameworks like CVSS to assess severity. Integrate vulnerability scanning tools with ticketing systems to assign remediation tasks based on criticality. - Use Case: A critical vulnerability with a CVSS score of 9.8 affecting remote access servers is prioritized and patched first.

*Tools for Implementation*

Open Source Tools:

- OpenVAS: Comprehensive network and system vulnerability scanning. - OWASP ZAP: Dynamic scanning of web applications for vulnerabilities. - Nmap with NSE Scripts: Network scanning with scripts to detect vulnerabilities.

Prevent users or groups from installing unauthorized or unapproved software to reduce the risk of introducing malicious or vulnerable applications. This can be achieved through allowlists, software restriction policies, endpoint management tools, and least privilege access principles. This mitigation can be implemented through the following measures:

Application Whitelisting

- Implement Microsoft AppLocker or Windows Defender Application Control (WDAC) to create and enforce allowlists for approved software. - Whitelist applications based on file hash, path, or digital signatures.

Restrict User Permissions

- Remove local administrator rights for all non-IT users. - Use Role-Based Access Control (RBAC) to restrict installation permissions to privileged accounts only.

Software Restriction Policies (SRP)

- Use GPO to configure SRP to deny execution of binaries from directories such as `%AppData%`, `%Temp%`, and external drives. - Restrict specific file types (`.exe`, `.bat`, `.msi`, `.js`, `.vbs`) to trusted directories only.

Endpoint Management Solutions

- Deploy tools like Microsoft Intune, SCCM, or Jamf for centralized software management. - Maintain a list of approved software, versions, and updates across the enterprise.

Monitor Software Installation Events

- Enable logging of software installation events and monitor Windows Event ID 4688 and Event ID 11707 for software installs. - Use SIEM or EDR tools to alert on attempts to install unapproved software.

Implement Software Inventory Management

- Use tools like OSQuery or Wazuh to scan for unauthorized software on endpoints and servers. - Conduct regular audits to detect and remove unapproved software.

*Tools for Implementation*

Application Whitelisting:

- Microsoft AppLocker - Windows Defender Application Control (WDAC)

Endpoint Management:

- Microsoft Intune - SCCM (System Center Configuration Manager) - Jamf Pro (macOS) - Puppet or Ansible for automation

Software Restriction Policies:

- Group Policy Object (GPO) - Microsoft Software Restriction Policies (SRP)

Monitoring and Logging:

- Splunk - OSQuery - Wazuh (open-source SIEM and XDR) - EDRs

Inventory Management and Auditing:

- OSQuery - Wazuh

Application Developer Guidance focuses on providing developers with the knowledge, tools, and best practices needed to write secure code, reduce vulnerabilities, and implement secure design principles. By integrating security throughout the software development lifecycle (SDLC), this mitigation aims to prevent the introduction of exploitable weaknesses in applications, systems, and APIs. This mitigation can be implemented through the following measures: Preventing SQL Injection (Secure Coding Practice):

- Implementation: Train developers to use parameterized queries or prepared statements instead of directly embedding user input into SQL queries. - Use Case: A web application accepts user input to search a database. By sanitizing and validating user inputs, developers can prevent attackers from injecting malicious SQL commands.

Cross-Site Scripting (XSS) Mitigation:

- Implementation: Require developers to implement output encoding for all user-generated content displayed on a web page. - Use Case: An e-commerce site allows users to leave product reviews. Properly encoding and escaping user inputs prevents malicious scripts from being executed in other users’ browsers.

Secure API Design:

- Implementation: Train developers to authenticate all API endpoints and avoid exposing sensitive information in API responses. - Use Case: A mobile banking application uses APIs for account management. By enforcing token-based authentication for every API call, developers reduce the risk of unauthorized access.

Static Code Analysis in the Build Pipeline:

- Implementation: Incorporate tools into CI/CD pipelines to automatically scan for vulnerabilities during the build process. - Use Case: A fintech company integrates static analysis tools to detect hardcoded credentials in their source code before deployment.

Threat Modeling in the Design Phase:

- Implementation: Use frameworks like STRIDE (Spoofing, Tampering, Repudiation, Information Disclosure, Denial of Service, Elevation of Privilege) to assess threats during application design. - Use Case: Before launching a customer portal, a SaaS company identifies potential abuse cases, such as session hijacking, and designs mitigations like secure session management.

**Tools for Implementation**:

- Static Code Analysis Tools: Use tools that can scan for known vulnerabilities in source code. - Dynamic Application Security Testing (DAST): Use tools like Burp Suite or OWASP ZAP to simulate runtime attacks and identify vulnerabilities. - Secure Frameworks: Recommend secure-by-default frameworks (e.g., Django for Python, Spring Security for Java) that enforce security best practices.

Boot Integrity ensures that a system starts securely by verifying the integrity of its boot process, operating system, and associated components. This mitigation focuses on leveraging secure boot mechanisms, hardware-rooted trust, and runtime integrity checks to prevent tampering during the boot sequence. It is designed to thwart adversaries attempting to modify system firmware, bootloaders, or critical OS components. This mitigation can be implemented through the following measures:

Implementation of Secure Boot:

- Implementation: Enable UEFI Secure Boot on all systems and configure it to allow only signed bootloaders and operating systems. - Use Case: An adversary attempts to replace the system’s bootloader with a malicious version to gain persistence. Secure Boot prevents the untrusted bootloader from executing, halting the attack.

Utilization of TPMs:

- Implementation: Configure systems to use TPM-based attestation for boot integrity, ensuring that any modification to the firmware, bootloader, or OS is detected. - Use Case: A compromised firmware component alters the boot sequence. The TPM detects the change and triggers an alert, allowing the organization to respond before further damage.

Enable Bootloader Passwords:

- Implementation: Protect BIOS/UEFI settings with a strong password and limit physical access to devices. - Use Case: An attacker with physical access attempts to disable Secure Boot or modify the boot sequence. The password prevents unauthorized changes.

Runtime Integrity Monitoring:

- Implementation: Deploy solutions to verify the integrity of critical files and processes after boot. - Use Case: A malware infection modifies kernel modules post-boot. Runtime integrity monitoring detects the modification and prevents the malicious module from loading.

User Account Management involves implementing and enforcing policies for the lifecycle of user accounts, including creation, modification, and deactivation. Proper account management reduces the attack surface by limiting unauthorized access, managing account privileges, and ensuring accounts are used according to organizational policies. This mitigation can be implemented through the following measures:

Enforcing the Principle of Least Privilege

- Implementation: Assign users only the minimum permissions required to perform their job functions. Regularly audit accounts to ensure no excess permissions are granted. - Use Case: Reduces the risk of privilege escalation by ensuring accounts cannot perform unauthorized actions.

Implementing Strong Password Policies

- Implementation: Enforce password complexity requirements (e.g., length, character types). Require password expiration every 90 days and disallow password reuse. - Use Case: Prevents adversaries from gaining unauthorized access through password guessing or brute force attacks.

Managing Dormant and Orphaned Accounts

- Implementation: Implement automated workflows to disable accounts after a set period of inactivity (e.g., 30 days). Remove orphaned accounts (e.g., accounts without an assigned owner) during regular account audits. - Use Case: Eliminates dormant accounts that could be exploited by attackers.

Account Lockout Policies

- Implementation: Configure account lockout thresholds (e.g., lock accounts after five failed login attempts). Set lockout durations to a minimum of 15 minutes. - Use Case: Mitigates automated attack techniques that rely on repeated login attempts.

Multi-Factor Authentication (MFA) for High-Risk Accounts

- Implementation: Require MFA for all administrative accounts and high-risk users. Use MFA mechanisms like hardware tokens, authenticator apps, or biometrics. - Use Case: Prevents unauthorized access, even if credentials are stolen.

Restricting Interactive Logins

- Implementation: Restrict interactive logins for privileged accounts to specific secure systems or management consoles. Use group policies to enforce logon restrictions. - Use Case: Protects sensitive accounts from misuse or exploitation.

*Tools for Implementation*

Built-in Tools:

- Microsoft Active Directory (AD): Centralized account management and RBAC enforcement. - Group Policy Object (GPO): Enforce password policies, logon restrictions, and account lockout policies.

Identity and Access Management (IAM) Tools:

- Okta: Centralized user provisioning, MFA, and SSO integration. - Microsoft Azure Active Directory: Provides advanced account lifecycle management, role-based access, and conditional access policies.

Privileged Account Management (PAM): - CyberArk, BeyondTrust, Thycotic: Manage and monitor privileged account usage, enforce session recording, and JIT access.

Software updates ensure systems are protected against known vulnerabilities by applying patches and upgrades provided by vendors. Regular updates reduce the attack surface and prevent adversaries from exploiting known security gaps. This includes patching operating systems, applications, drivers, and firmware. This mitigation can be implemented through the following measures:

Regular Operating System Updates

- Implementation: Apply the latest Windows security updates monthly using WSUS (Windows Server Update Services) or a similar patch management solution. Configure systems to check for updates automatically and schedule reboots during maintenance windows. - Use Case: Prevents exploitation of OS vulnerabilities such as privilege escalation or remote code execution.

Application Patching

- Implementation: Monitor Apache's update release notes for security patches addressing vulnerabilities. Schedule updates for off-peak hours to avoid downtime while maintaining security compliance. - Use Case: Prevents exploitation of web application vulnerabilities, such as those leading to unauthorized access or data breaches.

Firmware Updates

- Implementation: Regularly check the vendor’s website for firmware updates addressing vulnerabilities. Plan for update deployment during scheduled maintenance to minimize business disruption. - Use Case: Protects against vulnerabilities that adversaries could exploit to gain access to network devices or inject malicious traffic.

Emergency Patch Deployment

- Implementation: Use the emergency patch deployment feature of the organization's patch management tool to apply updates to all affected Exchange servers within 24 hours. - Use Case: Reduces the risk of exploitation by rapidly addressing critical vulnerabilities.

Centralized Patch Management

- Implementation: Implement a centralized patch management system, such as SCCM or ManageEngine, to automate and track patch deployment across all environments. Generate regular compliance reports to ensure all systems are updated. - Use Case: Streamlines patching processes and ensures no critical systems are missed.

*Tools for Implementation*

Patch Management Tools:

- WSUS: Manage and deploy Microsoft updates across the organization. - ManageEngine Patch Manager Plus: Automate patch deployment for OS and third-party apps. - Ansible: Automate updates across multiple platforms, including Linux and Windows.

Vulnerability Scanning Tools:

- OpenVAS: Open-source vulnerability scanning to identify missing patches.