T1550.001: Application Access Token

Restricting web-based content involves enforcing policies and technologies that limit access to potentially malicious websites, unsafe downloads, and unauthorized browser behaviors. This can include URL filtering, download restrictions, script blocking, and extension control to protect against exploitation, phishing, and malware delivery. This mitigation can be implemented through the following measures:

Deploy Web Proxy Filtering:

- Use solutions to filter web traffic based on categories, reputation, and content types. - Enforce policies that block unsafe websites or file types at the gateway level.

Enable DNS-Based Filtering:

- Implement tools to restrict access to domains associated with malware or phishing campaigns. - Use public DNS filtering services to enhance protection.

Enforce Content Security Policies (CSP):

- Configure CSP headers on internal and external web applications to restrict script execution, iframe embedding, and cross-origin requests.

Control Browser Features:

- Disable unapproved browser features like automatic downloads, developer tools, or unsafe scripting. - Enforce policies through tools like Group Policy Management to control browser settings.

Monitor and Alert on Web-Based Threats:

- Use SIEM tools to collect and analyze web proxy logs for signs of anomalous or malicious activity. - Configure alerts for access attempts to blocked domains or repeated file download failures.

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.

Auditing is the process of recording activity and systematically reviewing and analyzing the activity and system configurations. The primary purpose of auditing is to detect anomalies and identify potential threats or weaknesses in the environment. Proper auditing configurations can also help to meet compliance requirements. The process of auditing encompasses regular analysis of user behaviors and system logs in support of proactive security measures.

Auditing is applicable to all systems used within an organization, from the front door of a building to accessing a file on a fileserver. It is considered more critical for regulated industries such as, healthcare, finance and government where compliance requirements demand stringent tracking of user and system activates.This mitigation can be implemented through the following measures:

System Audit:

- Use Case: Regularly assess system configurations to ensure compliance with organizational security policies. - Implementation: Use tools to scan for deviations from established benchmarks.

Permission Audits:

- Use Case: Review file and folder permissions to minimize the risk of unauthorized access or privilege escalation. - Implementation: Run access reviews to identify users or groups with excessive permissions.

Software Audits:

- Use Case: Identify outdated, unsupported, or insecure software that could serve as an attack vector. - Implementation: Use inventory and vulnerability scanning tools to detect outdated versions and recommend secure alternatives.

Configuration Audits:

- Use Case: Evaluate system and network configurations to ensure secure settings (e.g., disabled SMBv1, enabled MFA). - Implementation: Implement automated configuration scanning tools like SCAP (Security Content Automation Protocol) to identify non-compliant systems.

Network Audits:

- Use Case: Examine network traffic, firewall rules, and endpoint communications to identify unauthorized or insecure connections. - Implementation: Utilize tools such as Wireshark, or Zeek to monitor and log suspicious network behavior.

Account Use Policies help mitigate unauthorized access by configuring and enforcing rules that govern how and when accounts can be used. These policies include enforcing account lockout mechanisms, restricting login times, and setting inactivity timeouts. Proper configuration of these policies reduces the risk of brute-force attacks, credential theft, and unauthorized access by limiting the opportunities for malicious actors to exploit accounts. This mitigation can be implemented through the following measures:

Account Lockout Policies:

- Implementation: Configure account lockout settings so that after a defined number of failed login attempts (e.g., 3-5 attempts), the account is locked for a specific time period (e.g., 15 minutes) or requires an administrator to unlock it. - Use Case: This prevents brute-force attacks by limiting how many incorrect password attempts can be made before the account is temporarily disabled, reducing the likelihood of an attacker successfully guessing a password.

Login Time Restrictions:

- Implementation: Set up login time policies to restrict when users or groups can log into systems. For example, only allowing login during standard business hours (e.g., 8 AM to 6 PM) for non-administrative accounts. - Use Case: This prevents unauthorized access outside of approved working hours, where login attempts might be more suspicious or harder to monitor. For example, if an account that is only supposed to be active during the day logs in at 2 AM, it should raise an alert or be blocked.

Inactivity Timeout and Session Termination:

- Implementation: Enforce session timeouts after a period of inactivity (e.g., 10-15 minutes) and require users to re-authenticate if they wish to resume the session. - Use Case: This policy prevents attackers from hijacking active sessions left unattended. For example, if an employee walks away from their computer without locking it, an attacker with physical access to the system would be unable to exploit the session.

Password Aging Policies:

- Implementation: Enforce password aging rules, requiring users to change their passwords after a defined period (e.g., 90 days) and ensure passwords are not reused by maintaining a password history. - Use Case: This limits the risk of compromised passwords being used indefinitely. Regular password changes make it more difficult for attackers to reuse stolen credentials.

Account Expiration and Deactivation:

- Implementation: Configure user accounts, especially for temporary or contract workers, to automatically expire after a set date or event. Accounts that remain unused for a specific period should be deactivated automatically. - Use Case: This prevents dormant accounts from becoming an attack vector. For example, an attacker can exploit unused accounts if they are not properly monitored or deactivated.

**Tools for Implementation**:

- Group Policy Objects (GPOs) in Windows: To enforce account lockout thresholds, login time restrictions, session timeouts, and password policies. - Identity and Access Management (IAM) solutions: For centralized management of user accounts, session policies, and automated deactivation of accounts. - Security Information and Event Management (SIEM) platforms: To monitor and alert on unusual login activity, such as failed logins or out-of-hours access attempts. - Multi-Factor Authentication (MFA) Tools: To further enforce secure login attempts, preventing brute-force or credential stuffing attacks.

Protect sensitive information at rest, in transit, and during processing by using strong encryption algorithms. Encryption ensures the confidentiality and integrity of data, preventing unauthorized access or tampering. This mitigation can be implemented through the following measures:

Encrypt Data at Rest:

- Use Case: Use full-disk encryption or file-level encryption to secure sensitive data stored on devices. - Implementation: Implement BitLocker for Windows systems or FileVault for macOS devices to encrypt hard drives.

Encrypt Data in Transit:

- Use Case: Use secure communication protocols (e.g., TLS, HTTPS) to encrypt sensitive data as it travels over networks. - Implementation: Enable HTTPS for all web applications and configure mail servers to enforce STARTTLS for email encryption.

Encrypt Backups:

- Use Case: Ensure that backup data is encrypted both during storage and transfer to prevent unauthorized access. - Implementation: Encrypt cloud backups using AES-256 before uploading them to Amazon S3 or Google Cloud.

Encrypt Application Secrets:

- Use Case: Store sensitive credentials, API keys, and configuration files in encrypted vaults. - Implementation: Use HashiCorp Vault or AWS Secrets Manager to manage and encrypt secrets.

Database Encryption:

- Use Case: Enable Transparent Data Encryption (TDE) or column-level encryption in database management systems. - Implementation: Use MySQL’s built-in encryption features to encrypt sensitive database fields such as social security numbers.