threat-modeling.md

Threat Model Analysis for apache/httpd

Threat: Exploiting Vulnerable Modules

Description: Attacker exploits known vulnerabilities in enabled Apache httpd modules (core or third-party). This can lead to Remote Code Execution (RCE), Denial of Service (DoS), or Information Disclosure depending on the vulnerability. Impact: Remote Code Execution, Denial of Service, Information Disclosure, potentially full server compromise. Affected Component: Specific httpd modules (e.g., mod_cgi, mod_php, etc.). Risk Severity: Critical to High Mitigation Strategies: * Regularly update all httpd modules to the latest versions. * Subscribe to security mailing lists and vulnerability databases for module updates. * Remove unused or unnecessary modules to reduce the attack surface. * Implement vulnerability scanning and patching processes for modules.

Threat: HTTP Request Smuggling

Description: Attacker exploits discrepancies in HTTP request parsing between front-end proxies and back-end Apache httpd. This allows them to "smuggle" requests, bypassing security controls, accessing unintended resources, or even poisoning caches. Impact: Security bypass, Unauthorized access to resources, Cache poisoning, Potential for further attacks and data breaches. Affected Component: Core httpd request parsing, interaction with front-end proxies. Risk Severity: High Mitigation Strategies: * Ensure consistent HTTP request parsing between front-end proxies and Apache httpd. * Disable or carefully configure features that might contribute to request smuggling vulnerabilities (e.g., chunked encoding, connection reuse). * Regularly update both front-end proxies and Apache httpd to the latest versions with security patches addressing request smuggling.

Threat: Configuration File Write Access (Privilege Escalation)

Description: Attacker gains write access to Apache httpd configuration files (e.g., via a web application vulnerability or compromised credentials). They can modify the configuration to execute arbitrary code with the privileges of the httpd process, potentially escalating to root privileges and gaining full control of the server. Impact: Privilege Escalation, Remote Code Execution, Full server compromise, Data breach, System takeover. Affected Component: Core httpd configuration files, file system permissions. Risk Severity: Critical Mitigation Strategies: * Restrict write access to Apache httpd configuration files to only authorized administrators and processes. * Implement file integrity monitoring to detect unauthorized modifications to configuration files. * Run Apache httpd with the least privileged user possible to limit the impact of potential compromises.

Threat: Vulnerabilities in Apache httpd Core

Description: Attacker exploits vulnerabilities in the core Apache httpd software itself. Exploiting these vulnerabilities can have severe consequences, including Remote Code Execution, Denial of Service, or Information Disclosure, potentially leading to full server compromise. Impact: Remote Code Execution, Denial of Service, Information Disclosure, Full server compromise, Data breach, System instability. Affected Component: Core httpd software. Risk Severity: Critical to High Mitigation Strategies: * Regularly update Apache httpd to the latest stable version with security patches. * Subscribe to Apache security mailing lists and vulnerability databases to stay informed about core vulnerabilities. * Implement a robust vulnerability management process to track, assess, and remediate vulnerabilities in Apache httpd promptly.

Threat: Compromised Distribution Packages

Description: Attacker uses compromised Apache httpd distribution packages containing malware or backdoors. This can lead to full server compromise from the initial installation, allowing persistent access, data theft, and malicious activities. Impact: Full server compromise, Malware infection, Data breach, Long-term persistent access for attackers. Affected Component: Apache httpd distribution packages. Risk Severity: Critical Mitigation Strategies: * Download Apache httpd from official and trusted sources only (e.g., apache.org, official OS repositories). * Verify the integrity of downloaded packages using checksums or digital signatures provided by the official source. * Implement security scanning of the Apache httpd installation and the entire system for malware and indicators of compromise.

Threat: Resource Exhaustion Denial of Service

Description: Attacker sends a large volume of requests (legitimate or slightly malformed) to overwhelm server resources like CPU, memory, or network bandwidth. If Apache httpd is not properly configured to handle resource limits, this can lead to service degradation or complete outage, preventing legitimate users from accessing the application. Impact: Denial of Service, Application unavailability, Performance degradation, Business disruption. Affected Component: Core httpd resource management, connection handling. Risk Severity: High Mitigation Strategies: * Implement rate limiting and request throttling at the application or infrastructure level (e.g., using mod_ratelimit, web application firewalls (WAFs), or load balancers). * Configure connection limits and timeouts in httpd configuration (e.g., Timeout, KeepAliveTimeout, MaxKeepAliveRequests). * Optimize application code and database queries to minimize resource consumption and improve server efficiency. * Implement resource monitoring and alerting to detect and respond to resource exhaustion attacks in real-time.