Description

Improper Privilege Management vulnerability in Apache HTTP Server's mod_ssl via SSLRequire and file-related expressions. This issue affects Apache HTTP Server: from 2.4.0 through 2.4.68.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.8",
  "pubDate": "2026-10-01T17:17:29.527Z",
  "pubdate": "2026-10-01T17:17:29.527Z",
  "executiveSummary": "This vulnerability involves an Improper Privilege Management flaw within the mod_ssl module of the Apache HTTP Server.\nThe issue manifests when utilizing SSLRequire directives in conjunction with file-related expressions, potentially allowing unauthorized access or privilege escalation.\nThe vulnerability affects Apache HTTP Server versions 2.4.0 through 2.4.68.\nImpact includes the potential for attackers to bypass security restrictions imposed by SSLRequire configurations, leading to unauthorized access to sensitive file resources.\nExploitation requires the target server to have specific mod_ssl configurations enabled, specifically those leveraging file-based access control expressions.\nRisk implications are high as this allows for the circumvention of established authentication and authorization policies, enabling an attacker to potentially read or interact with files they should otherwise be restricted from accessing.\nThe vulnerability does not necessarily require direct network authentication if the misconfiguration is exposed to the public-facing interface, though it depends on the specific path and file permissions involved in the deployment.",
  "technicalDetails": "The root cause of this vulnerability lies in the improper handling of privilege contexts within the mod_ssl module when processing SSLRequire directives that incorporate file-related expressions. Under specific conditions, the evaluation engine for these expressions may fail to correctly enforce the intended security constraints when accessing the underlying filesystem.\nThe vulnerable component is the mod_ssl module, which is responsible for providing strong cryptography for the Apache HTTP Server. Specifically, the logic used to interpret and enforce access control policies defined within the configuration files, particularly regarding SSLRequire, is susceptible to state inconsistencies during the request processing lifecycle.\nExploitation typically occurs when an attacker crafts a request that triggers the evaluation of a vulnerable SSLRequire expression. Because the engine performs improper privilege management, the evaluation may return a false-positive result or execute with elevated privileges, effectively granting the requester access to resources that should have been blocked.\nThe attack flow follows these steps: 1) Identification of an Apache HTTP Server instance running version 2.4.0 to 2.4.68 configured with sensitive file access protected by SSLRequire. 2) Analysis of the file-related expressions used in the configuration to identify potential logical paths for bypass. 3) Submission of a specifically crafted request designed to cause the mod_ssl engine to miscalculate the required privilege level during the directive evaluation. 4) Successful bypass of the security restriction, allowing the request to proceed to the file system handler, which then returns the contents of the restricted file or provides unauthorized execution context.\nThe vulnerability is limited to the scope of what the Apache process user can access on the filesystem. However, since the server process generally runs with elevated privileges or has access to critical configuration and web root files, this presents a significant privilege management risk.\nThere are no requirements for external authentication if the misconfigured resource is accessible via the web server's public-facing endpoint. The impact is significant as it facilitates unauthorized information disclosure or potential security policy circumvention."
}