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Mitigation Strategies Analysis for apache/httpd

Mitigation Strategy: Regular Security Audits of httpd Configuration

  • Description:
    1. Establish a schedule for regular audits of Apache httpd configuration files (e.g., monthly or quarterly).
    2. Identify all relevant configuration files, including httpd.conf, virtual host configuration files, .htaccess files (if used), and any module-specific configuration files.
    3. Utilize automated security scanning tools specifically designed for Apache configuration audits (e.g., Lynis, Nessus with appropriate plugins, or custom scripts using apachectl configtest).
    4. Manually review configuration files, focusing on security-sensitive directives such as Options, AllowOverride, Require, ServerSignature, ServerTokens, module configurations, and any custom configurations.
    5. Compare current configurations against security best practices and hardening guides (e.g., CIS benchmarks, vendor security recommendations).
    6. Document all findings, prioritize vulnerabilities based on severity, and create a remediation plan.
    7. Track the progress of remediation efforts and re-audit after changes are implemented to ensure effectiveness.
    • List of Threats Mitigated:
      • Misconfiguration Vulnerabilities (High Severity): Incorrect settings can directly lead to various exploits like directory traversal, information disclosure, or even remote code execution.
      • Information Disclosure (Medium Severity): Exposing unnecessary server information or directory listings can aid attackers in reconnaissance.
      • Privilege Escalation (Medium Severity): Misconfigured permissions or insecure module settings could potentially be exploited for privilege escalation.
    • Impact:
      • Misconfiguration Vulnerabilities: High reduction - Proactive identification and correction of misconfigurations significantly reduces the attack surface.
      • Information Disclosure: Moderate reduction - Audits help identify and rectify common information leakage points.
      • Privilege Escalation: Moderate reduction - Configuration reviews can uncover potential privilege-related weaknesses.
    • Currently Implemented: Yes, partially implemented. We perform manual configuration reviews annually before major releases.
    • Missing Implementation: Need to implement automated configuration scanning as part of our regular security checks and establish a more frequent audit schedule (quarterly) with documented findings and tracking.

Mitigation Strategy: Principle of Least Privilege for User Running httpd

  • Description:
    1. Identify the user account currently running the Apache httpd process. Check the User and Group directives in httpd.conf or process listings.
    2. Create a dedicated user and group specifically for running httpd (e.g., apache, www-data, httpd). Avoid using root or other administrative accounts.
    3. Change the User and Group directives in httpd.conf to the newly created user and group.
    4. Restrict file system permissions for this user and group. They should only have read and execute permissions on necessary files (e.g., web content, log directories, configuration files) and write permissions only to specific directories like log directories or temporary upload locations.
    5. If using CGI or SSI scripts, consider implementing Suexec or mod_ruid2 (or similar modules) to execute these scripts under different, even more restricted user identities. Configure these modules according to their documentation to ensure proper isolation.
    • List of Threats Mitigated:
      • Privilege Escalation (High Severity): If httpd runs as root and is compromised, attackers gain full system control. Running as a low-privileged user limits the impact.
      • System-Wide Compromise (High Severity): Restricting permissions limits the damage an attacker can do if they gain access through httpd.
      • Lateral Movement (Medium Severity): Reduced privileges hinder an attacker's ability to move laterally to other parts of the system after compromising httpd.
    • Impact:
      • Privilege Escalation: High reduction - Significantly reduces the risk of full system compromise if httpd is exploited.
      • System-Wide Compromise: High reduction - Limits the scope of damage from a successful attack on httpd.
      • Lateral Movement: Moderate reduction - Makes lateral movement more difficult for attackers.
    • Currently Implemented: Yes, implemented. Apache httpd runs under the www-data user.
    • Missing Implementation: Consider further isolating CGI scripts using Suexec or similar mechanisms for enhanced security, especially for applications heavily relying on CGI.

Mitigation Strategy: Disable Unnecessary Modules

  • Description:
    1. List all currently enabled Apache modules. This can be done using apachectl -M or by reviewing the LoadModule directives in httpd.conf.
    2. Analyze the application's functionality and identify the modules that are absolutely essential for its operation.
    3. Disable any modules that are not required. Comment out or remove the corresponding LoadModule lines in httpd.conf.
    4. Restart Apache httpd after disabling modules for the changes to take effect.
    5. Periodically review the list of enabled modules, especially after application updates or feature additions, to ensure only necessary modules are active.
    • List of Threats Mitigated:
      • Vulnerability Exploitation in Unused Modules (Medium to High Severity): Unused modules can contain vulnerabilities that attackers could exploit even if the module's functionality is not used by the application.
      • Denial of Service (DoS) (Low to Medium Severity): Unnecessary modules can consume resources, potentially contributing to DoS vulnerabilities.
      • Increased Attack Surface (Medium Severity): Each enabled module represents a potential entry point for attackers. Reducing modules minimizes the attack surface.
    • Impact:
      • Vulnerability Exploitation in Unused Modules: High reduction - Disabling unused modules eliminates the risk of vulnerabilities within them being exploited.
      • Denial of Service (DoS): Low reduction - Marginal improvement in resource usage, but not a primary DoS mitigation.
      • Increased Attack Surface: Moderate reduction - Reduces the overall attack surface by removing potential entry points.
    • Currently Implemented: Yes, partially implemented. We have disabled some obviously unnecessary modules like mod_info and mod_status.
    • Missing Implementation: Need to perform a thorough review of all enabled modules and disable any others that are not strictly required for the application's core functionality. This should be a recurring task during maintenance cycles.

Mitigation Strategy: Secure Default Settings and Disable Directory Listing

  • Description:
    1. Disable directory listing globally or per virtual host. Add Options -Indexes directive within the <Directory> block for the DocumentRoot in httpd.conf or virtual host configurations.
    2. Configure custom error pages using the ErrorDocument directive. Ensure these custom error pages are user-friendly and do not reveal sensitive server information, internal paths, or debugging details.
    3. Set ServerSignature Off and ServerTokens Prod in httpd.conf to suppress the Apache version and OS details in server responses.
    4. Review and harden other default settings as recommended by security best practices for Apache httpd. This might include setting appropriate timeouts, limiting request sizes, and configuring security headers.
    • List of Threats Mitigated:
      • Information Disclosure (Medium Severity): Directory listing allows attackers to browse server directories and potentially discover sensitive files.
      • Information Disclosure (Low Severity): Default error pages and server signatures can reveal server version and OS information, aiding reconnaissance.
      • Path Traversal (Low to Medium Severity): While not directly preventing path traversal, disabling directory listing makes it harder for attackers to discover exploitable paths.
    • Impact:
      • Information Disclosure (Directory Listing): High reduction - Directly prevents directory browsing and file discovery.
      • Information Disclosure (Server Info): Moderate reduction - Reduces information leakage about server software.
      • Path Traversal: Low reduction - Indirectly helps by making path discovery more difficult.
    • Currently Implemented: Yes, implemented. Options -Indexes, ServerSignature Off, and ServerTokens Prod are configured globally. We use default Apache error pages.
    • Missing Implementation: Need to implement custom error pages that are user-friendly and avoid revealing any sensitive information. This should be done for all virtual hosts.

Mitigation Strategy: Utilize Security-Focused Configuration Templates and Best Practices

  • Description:
    1. Identify and adopt a reputable security hardening guide or template for Apache httpd (e.g., CIS benchmarks, vendor-provided security guides, OWASP recommendations).
    2. Review the chosen guide thoroughly and understand the rationale behind each recommended configuration setting.
    3. Implement the recommended configurations in httpd.conf and virtual host files, carefully testing after each change to ensure no disruption to application functionality.
    4. Use configuration management tools (e.g., Ansible, Puppet, Chef) to automate the deployment and enforcement of secure configurations across all servers.
    5. Regularly update the configuration templates and best practices as new vulnerabilities are discovered and security recommendations evolve.
    • List of Threats Mitigated:
      • Wide Range of Vulnerabilities (Variable Severity): Security templates address a broad spectrum of potential misconfigurations and vulnerabilities.
      • Configuration Drift (Medium Severity): Using configuration management helps prevent configuration drift and ensures consistent security settings across environments.
    • Impact:
      • Wide Range of Vulnerabilities: High reduction - Comprehensive security templates address many common and less obvious security weaknesses.
      • Configuration Drift: Moderate reduction - Helps maintain consistent and secure configurations over time.
    • Currently Implemented: No, not implemented. We are using a basic default configuration with some manual hardening.
    • Missing Implementation: Need to adopt a security hardening standard like CIS benchmarks and implement it using configuration management tools. This is a significant improvement we should prioritize.

Mitigation Strategy: Restrict Access to Configuration Files

  • Description:
    1. Identify the location of all Apache httpd configuration files (e.g., httpd.conf, virtual host files, module configuration files).
    2. Set file system permissions on these files to restrict read and write access. Only the root user and the user running the configuration management system (if applicable) should have write access. The user running httpd should only have read access if necessary (though often not required).
    3. Ensure that backup copies of configuration files are also stored securely and access-controlled.
    4. Regularly review file permissions to ensure they remain restrictive and prevent unauthorized access or modification.
    • List of Threats Mitigated:
      • Unauthorized Configuration Changes (High Severity): Attackers gaining write access to configuration files can completely compromise the web server and potentially the application.
      • Information Disclosure (Medium Severity): Reading configuration files can reveal sensitive information like database credentials, API keys (if embedded), or internal server settings.
    • Impact:
      • Unauthorized Configuration Changes: High reduction - Strict access control prevents unauthorized modification of critical server settings.
      • Information Disclosure: Moderate reduction - Protects sensitive information potentially stored in configuration files.
    • Currently Implemented: Yes, partially implemented. Configuration files are owned by root and have restricted permissions, but we haven't explicitly reviewed and hardened permissions recently.
    • Missing Implementation: Need to perform a dedicated review of permissions on all configuration files and ensure they adhere to the principle of least privilege. Document the intended permissions and regularly audit them.

Mitigation Strategy: Regularly Update Apache httpd to the Latest Stable Version

  • Description:
    1. Establish a process for regularly checking for updates to Apache httpd. Subscribe to security mailing lists from the Apache Software Foundation or use vulnerability monitoring services.
    2. Test updates in a staging or development environment before deploying them to production. This includes functional testing and regression testing to ensure compatibility and stability.
    3. Implement an automated update mechanism where feasible (e.g., using package managers like apt, yum, or configuration management tools). Ensure this automation includes testing and rollback capabilities.
    4. Prioritize security updates and apply them promptly, especially for critical vulnerabilities.
    5. Keep track of the current Apache httpd version in use and document the update history.
    • List of Threats Mitigated:
      • Exploitation of Known Vulnerabilities (High Severity): Outdated software is vulnerable to publicly known exploits. Updating patches these vulnerabilities.
      • Zero-Day Vulnerabilities (Medium Severity): While updates don't directly prevent zero-days, staying up-to-date often includes general security improvements that can make exploitation harder.
    • Impact:
      • Exploitation of Known Vulnerabilities: High reduction - Significantly reduces the risk of exploitation via known vulnerabilities.
      • Zero-Day Vulnerabilities: Low reduction - Indirectly improves overall security posture, but not a direct mitigation for zero-days.
    • Currently Implemented: Yes, partially implemented. We apply OS-level security updates regularly, which includes Apache httpd, but we don't have a dedicated process for tracking Apache-specific updates and testing them separately.
    • Missing Implementation: Need to establish a more proactive process for monitoring Apache httpd specific security advisories, testing updates in a staging environment, and implementing a more streamlined update deployment process, potentially with automation.

Mitigation Strategy: Keep Modules Updated and Monitor Module-Specific Security Advisories

  • Description:
    1. Maintain an inventory of all enabled Apache modules and their versions.
    2. Monitor security advisories and vulnerability databases specifically for the modules in use (e.g., check the Apache Security mailing lists, CVE databases, and module-specific websites if available).
    3. When updates or patches are released for modules, prioritize applying them, especially for security-related fixes.
    4. Test module updates in a staging environment before deploying to production to ensure compatibility and stability.
    5. Implement a process for regularly reviewing module versions and checking for available updates.
    • List of Threats Mitigated:
      • Vulnerability Exploitation in Modules (Medium to High Severity): Modules can contain vulnerabilities that can be exploited if not updated.
      • Compromise through Module Weaknesses (Medium Severity): Vulnerable modules can be entry points for attackers to compromise the server or application.
    • Impact:
      • Vulnerability Exploitation in Modules: High reduction - Updating modules patches known vulnerabilities and reduces the risk of exploitation.
      • Compromise through Module Weaknesses: Moderate reduction - Reduces the likelihood of compromise through module-specific vulnerabilities.
    • Currently Implemented: No, not implemented. We generally update Apache through OS updates, but we don't specifically track module versions or module-specific advisories.
    • Missing Implementation: Need to implement a system for tracking Apache module versions, monitoring module-specific security advisories, and a process for testing and applying module updates independently of full Apache updates when necessary.

Mitigation Strategy: Only Use Necessary and Trusted Modules

  • Description:
    1. Before enabling any new Apache module, thoroughly evaluate its necessity for the application's functionality.
    2. Research the module's security history and reputation. Check for known vulnerabilities, security advisories, and the module's maintenance status.
    3. Prefer modules from reputable sources (e.g., official Apache modules, well-known and actively maintained third-party modules).
    4. Avoid using modules that are outdated, unmaintained, or have a history of security issues unless absolutely necessary and with careful risk assessment.
    5. Regularly review the list of enabled modules and re-evaluate the necessity and security posture of each module.
    • List of Threats Mitigated:
      • Vulnerability Introduction through Modules (Medium to High Severity): Using untrusted or poorly maintained modules increases the risk of introducing vulnerabilities.
      • Increased Attack Surface (Medium Severity): Each module adds to the attack surface. Using only necessary modules minimizes this.
      • Backdoor or Malicious Modules (High Severity - if using truly untrusted sources): In rare cases, malicious modules could be introduced, leading to severe compromise.
    • Impact:
      • Vulnerability Introduction through Modules: High reduction - Careful module selection significantly reduces the risk of introducing vulnerable components.
      • Increased Attack Surface: Moderate reduction - Minimizes the attack surface by limiting the number of active components.
      • Backdoor or Malicious Modules: Low to Moderate reduction - Reduces the risk if modules are chosen from reputable sources, but vigilance is still needed.
    • Currently Implemented: Yes, partially implemented. We generally only enable modules we believe are necessary, but we don't have a formal process for security vetting new modules.
    • Missing Implementation: Need to establish a formal process for evaluating the security and necessity of any new Apache modules before enabling them. This should include researching the module's reputation and security history.

Mitigation Strategy: Implement Request Timeouts with mod_reqtimeout

  • Description:
    1. Ensure the mod_reqtimeout module is enabled in Apache.
    2. Configure timeout directives within httpd.conf or virtual host configurations. Key directives include:
      • RequestReadTimeout header=<seconds>-<seconds>,body=<seconds>-<seconds>: Sets timeouts for reading request headers and body. The first value is for the initial read, the second for subsequent reads.
      • RequestHeaderTimeout <seconds>: Sets a timeout for receiving the entire request header.
      • RequestBodyTimeout <seconds>: Sets a timeout for receiving the entire request body.
    3. Set appropriate timeout values based on the application's expected request processing times and tolerance for slow clients. Start with conservative values and adjust based on monitoring and testing.
    4. Test the timeout configurations to ensure they are effective in mitigating slowloris-style attacks and do not negatively impact legitimate users with slow connections.
    • List of Threats Mitigated:
      • Slowloris DoS Attacks (High Severity): mod_reqtimeout is specifically designed to mitigate slowloris and similar slow-connection DoS attacks.
      • Slow HTTP Header/Body Attacks (High Severity): Timeouts prevent attackers from holding connections open indefinitely by slowly sending headers or body.
      • Resource Exhaustion DoS (Medium Severity): By closing slow connections, mod_reqtimeout helps prevent resource exhaustion from numerous stalled connections.
    • Impact:
      • Slowloris DoS Attacks: High reduction - Effectively mitigates slowloris attacks by enforcing connection timeouts.
      • Slow HTTP Header/Body Attacks: High reduction - Prevents attacks that rely on slowly sending request data.
      • Resource Exhaustion DoS: Moderate reduction - Helps reduce resource consumption from slow connections, but not a complete DoS solution.
    • Currently Implemented: No, not implemented. We are not currently using mod_reqtimeout.
    • Missing Implementation: Need to enable mod_reqtimeout and configure appropriate RequestReadTimeout settings in our httpd.conf or virtual host configurations. This is a recommended step to improve DoS resilience.

Mitigation Strategy: Employ Rate Limiting with mod_ratelimit or mod_qos

  • Description:
    1. Choose a rate limiting module (e.g., mod_ratelimit for basic rate limiting, mod_qos for more advanced QoS features). Ensure the chosen module is enabled.
    2. Configure rate limiting rules in httpd.conf or virtual host configurations.
      • For mod_ratelimit, use the RateLimit directive to set a bandwidth limit per connection or per IP address.
      • For mod_qos, configure directives like QS_ClientEntries, QS_SrvMaxConnPerIP, QS_LimitRequestLine, QS_LimitRequestBody, etc., to control connection limits, request rates, and request sizes.
    3. Define appropriate rate limits based on expected traffic patterns and application requirements. Start with moderate limits and adjust based on monitoring and testing.
    4. Monitor rate limiting effectiveness and adjust configurations as needed to balance security and legitimate user access.
    • List of Threats Mitigated:
      • Brute-Force Attacks (High Severity): Rate limiting slows down brute-force attempts by limiting login attempts or request rates.
      • Denial of Service (DoS) (Medium Severity): Rate limiting can mitigate some forms of DoS attacks by limiting the number of requests from a single source.
      • Excessive Crawling/Scraping (Low to Medium Severity): Rate limiting can control aggressive web crawlers or scrapers that can overload the server.
    • Impact:
      • Brute-Force Attacks: High reduction - Significantly slows down brute-force attempts, making them less effective.
      • Denial of Service (DoS): Moderate reduction - Can mitigate some types of DoS, especially those originating from a single source, but not distributed DoS.
      • Excessive Crawling/Scraping: Moderate reduction - Helps control resource usage from aggressive crawlers.
    • Currently Implemented: No, not implemented. We do not currently have rate limiting configured at the Apache level.
    • Missing Implementation: Need to implement rate limiting using mod_ratelimit or mod_qos. mod_ratelimit might be a good starting point for basic rate limiting. We should configure limits per IP address to protect against brute-force and some DoS attempts.

Mitigation Strategy: Utilize a Web Application Firewall (WAF) like mod_security

  • Description:
    1. Install and enable the mod_security module (or another WAF module).
    2. Configure mod_security with a robust rule set (e.g., OWASP ModSecurity Core Rule Set - CRS). Download and integrate the CRS into the mod_security configuration.
    3. Customize the WAF rules to fit the specific application's needs and security requirements. This may involve tuning rule sensitivity, whitelisting legitimate traffic, and creating custom rules.
    4. Set the mod_security engine to "DetectionOnly" initially to monitor traffic and identify potential false positives. After tuning, switch to "On" to actively block malicious requests.
    5. Regularly update the WAF rule set to protect against new and emerging threats.
    6. Monitor WAF logs and alerts to identify and respond to security incidents.
    • List of Threats Mitigated:
      • SQL Injection (High Severity): WAFs can detect and block SQL injection attempts.
      • Cross-Site Scripting (XSS) (High Severity): WAFs can filter out XSS payloads in requests and responses.
      • Remote File Inclusion (RFI) (High Severity): WAFs can detect and block RFI attacks.
      • Command Injection (High Severity): WAFs can identify and block command injection attempts.
      • Many other web application attacks (Variable Severity): WAFs provide broad protection against various web application vulnerabilities.
      • Some DoS attacks (Medium Severity): WAFs can mitigate some application-layer DoS attacks.
    • Impact:
      • SQL Injection: High reduction - WAFs are very effective at mitigating SQL injection.
      • Cross-Site Scripting (XSS): High reduction - WAFs provide strong protection against XSS.
      • Remote File Inclusion (RFI): High reduction - WAFs can effectively block RFI attacks.
      • Command Injection: High reduction - WAFs can detect and block command injection.
      • Many other web application attacks: High reduction - Provides broad protection against a wide range of web attacks.
      • Some DoS attacks: Moderate reduction - Can mitigate some application-layer DoS, but not network-layer DoS.
    • Currently Implemented: No, not implemented. We do not currently have a WAF in place at the Apache level.
    • Missing Implementation: Implementing a WAF like mod_security with the OWASP CRS is a significant security enhancement we should prioritize. This will provide broad protection against many web application attacks.

Mitigation Strategy: Configure Resource Limits (LimitRequest* Directives)

  • Description:
    1. Configure Apache's LimitRequest* directives in httpd.conf or virtual host configurations:
      • LimitRequestBody <bytes>: Limits the maximum size of the HTTP request body.
      • LimitRequestFields <number>: Limits the number of HTTP request header fields.
      • LimitRequestLine <bytes>: Limits the maximum size of the HTTP request line (method, URI, protocol).
    2. Set appropriate resource limits based on the application's expected resource usage and server capacity. Start with reasonable limits and adjust based on monitoring and testing.
    3. Monitor resource usage and adjust limits as needed to prevent resource exhaustion and ensure application stability.
    • List of Threats Mitigated:
      • Resource Exhaustion DoS (High Severity): Resource limits prevent attackers from consuming excessive server resources (CPU, memory, file descriptors) and causing a DoS.
      • Slowloris and similar DoS (Medium Severity): LimitRequestBody can help mitigate attacks that send very large request bodies slowly.
      • Header/Field Overflow Attacks (Medium Severity): LimitRequestFields and LimitRequestLine prevent attacks that send excessively large headers or request lines to cause buffer overflows or resource exhaustion.
    • Impact:
      • Resource Exhaustion DoS: High reduction - Resource limits effectively prevent resource exhaustion attacks.
      • Slowloris and similar DoS: Moderate reduction - LimitRequestBody provides some mitigation against attacks involving large bodies.
      • Header/Field Overflow Attacks: Moderate reduction - Limits protect against attacks exploiting header/field overflows.
    • Currently Implemented: No, not implemented. We have not configured LimitRequest* directives in Apache.
    • Missing Implementation: We should configure LimitRequestBody, LimitRequestFields, and LimitRequestLine directives in Apache to further limit request sizes and complexity.

Mitigation Strategy: Disable Server Signature and Version Information

  • Description:
    1. In httpd.conf or virtual host configurations, set the following directives:
      • ServerSignature Off: This directive prevents Apache from adding a line containing server version and virtual host information to server-generated documents (like error pages).
      • ServerTokens Prod: This directive controls the information that Apache sends in the Server HTTP header. Setting it to Prod will only send "Apache" in the header, without version details or OS information. Other options like OS, Minor, Major, Minimal, and Full reveal varying levels of detail.
    2. Restart Apache httpd after making these changes.
    3. Verify the changes by sending a request to the server and inspecting the Server header in the response and checking error pages.
    • List of Threats Mitigated:
      • Information Disclosure (Low Severity): Revealing server version and OS information can aid attackers in reconnaissance by identifying known vulnerabilities in specific versions.
    • Impact:
      • Information Disclosure: Moderate reduction - Reduces information leakage that could be used for reconnaissance.
    • Currently Implemented: Yes, implemented. ServerSignature Off and ServerTokens Prod are configured globally in httpd.conf.
    • Missing Implementation: N/A - Fully implemented.

Mitigation Strategy: Remove or Restrict Access to Server-Status and Server-Info Pages

  • Description:
    1. Identify if mod_status and mod_info modules are enabled. Check for LoadModule directives for mod_status.so and mod_info.so in httpd.conf.
    2. If these modules are not needed, disable them by commenting out or removing the LoadModule lines and restarting Apache.
    3. If mod_status is needed for monitoring, restrict access to the /server-status page using <Location /server-status> and Require directives. Restrict access to specific IP addresses or require authentication. Example: apache <Location /server-status> SetHandler server-status Require ip 192.168.1.0/24 10.0.0.0/8 # Or require valid-user for authentication </Location>
    4. Similarly, if mod_info is enabled and needed, restrict access to /server-info using <Location /server-info> and Require directives.
    • List of Threats Mitigated:
      • Information Disclosure (Medium Severity): server-status and server-info pages can reveal sensitive server configuration details, module information, and runtime statistics if accessible to unauthorized users.
    • Impact:
      • Information Disclosure: High reduction - Restricting access or disabling these modules prevents unauthorized access to sensitive server information.
    • Currently Implemented: Yes, partially implemented. mod_info is disabled. mod_status is enabled but not restricted.
    • Missing Implementation: Need to restrict access to the /server-status page to authorized IP addresses or require authentication. This is important to prevent unauthorized access to server statistics.

Mitigation Strategy: Carefully Configure Error Pages to Avoid Revealing Sensitive Information

  • Description:
    1. Configure custom error pages using the ErrorDocument directive in httpd.conf or virtual host configurations.
    2. Create custom error page files (e.g., 404.html, 500.html) that are user-friendly and informative but do not reveal sensitive server information, internal paths, application details, or debugging information.
    3. Ensure custom error pages do not display stack traces, configuration details, or any information that could aid attackers in understanding the application's internal workings.
    4. Test the custom error pages to ensure they are displayed correctly and do not leak sensitive information.
    • List of Threats Mitigated:
      • Information Disclosure (Low to Medium Severity): Default error pages can reveal internal server paths, application frameworks, or debugging information, aiding reconnaissance.
    • Impact:
      • Information Disclosure: Moderate reduction - Custom error pages prevent leakage of sensitive information through default error responses.
    • Currently Implemented: Yes, partially implemented. We use default Apache error pages.
    • Missing Implementation: Need to create and configure custom error pages for common HTTP error codes (404, 500, etc.) that are user-friendly and avoid revealing any sensitive server or application details.

Mitigation Strategy: Properly Configure DocumentRoot and Virtual Host Configurations

  • Description:
    1. Carefully define the DocumentRoot directive in httpd.conf or virtual host configurations for each website or application hosted on the server.
    2. Ensure that DocumentRoot points to the intended web root directory, which should contain only the publicly accessible files and directories of the application.
    3. Avoid setting DocumentRoot to overly broad paths like the system root directory (/) or parent directories that could expose sensitive files or directories outside the intended web application scope.
    4. For virtual hosts, configure separate DocumentRoot directives for each virtual host to isolate web content and prevent cross-site access.
    5. Regularly review DocumentRoot configurations to ensure they are correctly set and do not expose unintended files or directories.
    • List of Threats Mitigated:
      • Directory Traversal (High Severity): Incorrect DocumentRoot configuration can make directory traversal vulnerabilities easier to exploit by exposing more of the file system.
      • Information Disclosure (Medium Severity): Broad DocumentRoot settings can unintentionally expose sensitive files or directories to web access.
    • Impact:
      • Directory Traversal: Moderate reduction - Proper DocumentRoot configuration limits the scope of potential directory traversal vulnerabilities.
      • Information Disclosure: Moderate reduction - Reduces the risk of unintentionally exposing sensitive files through web access.
    • Currently Implemented: Yes, implemented. DocumentRoot is correctly configured for each virtual host to point to the intended web root directory.
    • Missing Implementation: N/A - Fully implemented.

Mitigation Strategy: Use <Directory> Directives to Restrict Access

  • Description:
    1. Utilize <Directory> directives in httpd.conf or virtual host configurations to explicitly control access permissions for specific directories within the web server's file system.
    2. Use Options directives within <Directory> blocks to control directory features like indexing, CGI execution, and server-side includes. For security, often Options -Indexes +FollowSymLinks -ExecCGI -Includes is a good starting point.
    3. Use AllowOverride None within <Directory> blocks to disable .htaccess files in those directories, preventing local overrides of security settings.
    4. Use Require directives within <Directory> blocks to restrict access based on IP addresses, hostnames, or authentication requirements. Examples:
      • Require ip 192.168.1.0/24: Allow access only from the 192.168.1.0/24 network.
      • Require host example.com: Allow access only from hosts in the example.com domain.
      • Require valid-user: Require authentication for access.
    5. Apply <Directory> restrictions to sensitive directories, such as application configuration directories, data directories, or any directories that should not be publicly accessible.
    • List of Threats Mitigated:
      • Directory Traversal (High Severity): <Directory> restrictions can prevent access to sensitive directories, mitigating directory traversal attempts.
      • Unauthorized Access (High Severity): Require directives enforce access control, preventing unauthorized users from accessing protected directories.
      • Information Disclosure (Medium Severity): Restricting access to sensitive directories prevents information disclosure through directory browsing or direct file access.
    • Impact:
      • Directory Traversal: High reduction - Effectively prevents access to restricted directories, mitigating directory traversal.
      • Unauthorized Access: High reduction - Enforces access control and prevents unauthorized access.
      • Information Disclosure: High reduction - Prevents information leakage by restricting access to sensitive directories.
    • Currently Implemented: Yes, partially implemented. We use <Directory> blocks for DocumentRoot and some specific directories, but we haven't systematically reviewed and applied restrictions to all sensitive directories.
    • Missing Implementation: Need to perform a comprehensive review of our directory structure and implement <Directory> restrictions with appropriate Options and Require directives for all sensitive directories that should not be publicly accessible. This includes configuration directories, data directories, and any internal application directories.

Mitigation Strategy: Disable Directory Listing (as mentioned earlier)

  • Description:
    1. Ensure directory listing is disabled globally or per virtual host by adding Options -Indexes directive within the <Directory> block for the DocumentRoot in httpd.conf or virtual host configurations.
    2. Verify that directory listing is disabled by attempting to access a directory without an index file in a web browser. You should receive a "Forbidden" error or a custom error page instead of a directory listing.
    • List of Threats Mitigated:
      • Information Disclosure (Medium Severity): Directory listing allows attackers to browse server directories and potentially discover sensitive files.
      • Path Traversal (Low to Medium Severity): While not directly preventing path traversal, disabling directory listing makes it harder for attackers to discover exploitable paths.
    • Impact:
      • Information Disclosure: High reduction - Directly prevents directory browsing and file discovery.
      • Path Traversal: Low reduction - Indirectly helps by making path discovery more difficult.
    • Currently Implemented: Yes, implemented. Options -Indexes is configured globally in httpd.conf.
    • Missing Implementation: N/A - Fully implemented.