CVE-2025-58098 is a vulnerability classified under CWE-201 (Insertion of Sensitive Information Into Sent Data) affecting Apache HTTP Server versions 2.4.65 and earlier. The issue specifically arises when Server Side Includes (SSI) are enabled alongside the mod_cgid module (but not mod_cgi). In this configuration, the server passes the shell-escaped query string directly to the #exec cmd="..." directives within SSI. This behavior can inadvertently expose sensitive information by inserting it into data sent to clients or other systems, potentially leading to information disclosure and command injection risks. The vulnerability requires only low privileges (PR:L), no user interaction (UI:N), and can be exploited remotely (AV:N), making it a significant threat. The impact affects confidentiality and integrity primarily, with some availability impact possible. The flaw was addressed in Apache HTTP Server version 2.4.66, which corrects the handling of query strings in SSI #exec commands to prevent sensitive data leakage. No known exploits are currently in the wild, but the high CVSS score (8.3) indicates a serious risk if exploited. Organizations using Apache HTTP Server with SSI and mod_cgid should prioritize upgrading and reviewing their server configurations to mitigate exposure.

For European organizations, this vulnerability poses a significant risk of sensitive data leakage and potential command injection attacks on web servers running vulnerable Apache HTTP Server versions with SSI and mod_cgid enabled. Confidentiality breaches could expose internal query parameters or other sensitive information embedded in URLs, impacting customer data privacy and intellectual property. Integrity could be compromised if attackers manipulate commands executed via SSI directives, potentially leading to unauthorized actions or system compromise. Availability impact is lower but possible if exploitation leads to server instability. Given Apache HTTP Server’s widespread use across European enterprises, government agencies, and critical infrastructure, successful exploitation could disrupt services, erode trust, and lead to regulatory penalties under GDPR for data breaches. The remote and low-privilege nature of the exploit increases the threat surface, especially for externally facing web servers. Organizations relying on legacy Apache versions or complex SSI configurations are particularly vulnerable.

1. Immediately upgrade all Apache HTTP Server instances to version 2.4.66 or later, where the vulnerability is fixed. 2. Audit server configurations to identify and disable Server Side Includes (SSI) where not strictly necessary, especially in combination with mod_cgid. 3. If SSI is required, consider disabling mod_cgid or replacing it with mod_cgi if feasible, as the vulnerability does not affect mod_cgi. 4. Review and sanitize all query string inputs and avoid passing untrusted data to #exec cmd directives. 5. Implement strict access controls and monitoring on web servers to detect anomalous SSI command executions. 6. Employ web application firewalls (WAFs) with rules targeting suspicious SSI usage patterns. 7. Conduct penetration testing focusing on SSI and mod_cgid interactions to verify mitigation effectiveness. 8. Maintain up-to-date inventory of Apache versions and configurations to quickly respond to emerging vulnerabilities.