CVE-2025-65082 is a security vulnerability classified under CWE-150 (Improper Neutralization of Escape, Meta, or Control Sequences) affecting the Apache HTTP Server versions 2.4.0 through 2.4.65. The issue arises from the way environment variables are handled within the Apache configuration, where variables set explicitly by administrators can unexpectedly override those that the server calculates internally for CGI (Common Gateway Interface) programs. This improper neutralization can allow specially crafted environment variables to inject escape sequences or control characters, potentially leading to injection attacks or unintended command execution within CGI scripts. Since CGI programs often run with elevated privileges or access sensitive resources, this vulnerability can compromise server integrity and confidentiality. The flaw does not require user interaction or authentication to be exploited if an attacker can influence the Apache configuration or environment variables, which might be possible through misconfigurations or chained vulnerabilities. Apache HTTP Server version 2.4.66 addresses this issue by correcting the environment variable handling logic to prevent such overrides. No public exploits have been reported so far, but the vulnerability's nature makes it a significant risk for servers running vulnerable versions, especially those exposing CGI interfaces. The vulnerability was reserved and published in late 2025, indicating recent discovery and patch availability. Organizations relying on Apache HTTP Server for web services, particularly those using CGI scripts, should urgently assess their exposure and apply the update.

For European organizations, this vulnerability poses a risk to web servers running Apache HTTP Server versions 2.4.0 through 2.4.65, especially those utilizing CGI programs. Exploitation could allow attackers to inject malicious commands or manipulate environment variables, potentially leading to unauthorized code execution, data leakage, or server compromise. This can disrupt service availability, breach confidentiality of sensitive data, and undermine integrity of hosted applications. Given the widespread use of Apache HTTP Server across European enterprises, government agencies, and hosting providers, the impact could be significant, particularly for sectors relying on CGI-based legacy applications. The vulnerability could facilitate lateral movement or privilege escalation within networks if exploited in conjunction with other weaknesses. Additionally, the lack of known exploits currently provides a window for proactive mitigation, but also means organizations must act swiftly to prevent future attacks. The impact is heightened in environments where patch management is slow or where legacy CGI applications are critical to business operations.

The primary mitigation is to upgrade Apache HTTP Server to version 2.4.66 or later, which contains the fix for this vulnerability. Organizations should implement this update promptly across all affected servers. Beyond patching, administrators should audit Apache configurations to identify and minimize the use of environment variables that could be manipulated or override server-calculated variables, especially in CGI contexts. Restricting access to Apache configuration files and limiting who can modify environment variables reduces risk. Employing application-layer firewalls or web application firewalls (WAFs) that can detect anomalous CGI requests may provide additional protection. Regularly reviewing CGI scripts for secure coding practices and minimizing CGI usage where possible can reduce the attack surface. Monitoring server logs for unusual environment variable settings or unexpected CGI behavior can help detect attempted exploitation. Finally, integrating this vulnerability into vulnerability management and incident response processes ensures ongoing awareness and readiness.