medium CVSS 6.5

CVE-2025-65082·Apache vulnerability

Improper Neutralization of Escape, Meta, or Control Sequences vulnerability in Apache HTTP Server through environment variables set via the Apache configuration unexpectedly superseding variables calculated by the server for CGI programs. This issue affects Apache HTTP Server from 2.4.0 through 2.4.65. Users are recommended to upgrade to version 2.4.66 which fixes the issue.

Severity
medium
Software
Apache
Fixed in
2.4.66
Published
2025-12-05

Affected versions

From: 2.4.0

Until: 2.4.66

Fixed in: 2.4.66

How to fix this CVE

Apache HTTP Server versions 2.4.0 through 2.4.65 contain a vulnerability where configuration-defined environment variables can override server-calculated variables passed to CGI programs, potentially leading to information disclosure or request manipulation. Upgrade to Apache 2.4.66 or later to resolve this issue. Review your CGI applications and environment variable configurations after patching to ensure no unintended behavior changes.

sudo dnf update httpd httpd-tools

Defensia detects this vulnerability

How to check if you are affected

  1. Check installed Apache version with: apache2ctl -v (or httpd -v on RHEL/CentOS/Amazon Linux)
  2. Verify CGI is enabled by checking for mod_cgi or mod_cgid in: apache2ctl -M | grep cgi (or httpd -M on RHEL/CentOS)
  3. Search Apache access and error logs for CGI requests with suspicious environment variable patterns: grep -E 'CGI|REMOTE_|SERVER_' /var/log/apache2/error.log
  4. After upgrading, confirm version with apache2ctl -v and restart Apache: sudo systemctl restart apache2 (or httpd on RHEL/CentOS)

FAQ

What is CVE-2025-65082?

This vulnerability allows Apache configuration directives to set environment variables that improperly override internally calculated variables before they reach CGI programs. This can lead to CGI scripts receiving modified or spoofed environment values, potentially bypassing security controls or leaking sensitive information.

Is CVE-2025-65082 being actively exploited?

No, this vulnerability is not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog and no public exploits are available. However, timely patching remains critical for environments running CGI applications.

What versions of Apache are affected by CVE-2025-65082?

Apache HTTP Server versions 2.4.0 through 2.4.65 are vulnerable. Version 2.4.66 and later contain the fix.

How do I check if my server is vulnerable to CVE-2025-65082?

Run apache2ctl -v (or httpd -v) and check if the version is between 2.4.0 and 2.4.65. If yes, and you have CGI enabled (verify with apache2ctl -M | grep cgi), your server is vulnerable.

Does Defensia detect CVE-2025-65082?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Apache is installed on a monitored server, CVE-2025-65082 will appear in your dashboard with remediation steps.

Related Apache CVEs

CVE-2024-38476CVSS 9.8Vulnerability in core of Apache HTTP Server 2.4.59 and earlier are vulnerably to information disclosure, SSRF or local script execution via backend applications whose response headers are malicious or exploitable. Users are recommended to upgrade to version 2.4.60, which fixes this issue.
CVE-2024-38474CVSS 9.8Substitution encoding issue in mod_rewrite in Apache HTTP Server 2.4.59 and earlier allows attacker to execute scripts in directories permitted by the configuration but not directly reachable by any URL or source disclosure of scripts meant to only to be executed as CGI. Users are recommended to upgrade to version 2.4.60, which fixes this issue. Some RewriteRules that capture and substitute unsafely will now fail unless rewrite flag "UnsafeAllow3F" is specified.
CVE-2026-28780CVSS 9.8Heap-based Buffer Overflow vulnerability in mod_proxy_ajp of Apache HTTP Server. If mod_proxy_ajp connects to a malicious AJP server this AJP server can send a malicious AJP message back to mod_proxy_ajp and cause it to write 4 attacker controlled bytes after the end of a heap based buffer. This issue affects Apache HTTP Server: through 2.4.66. Users are recommended to upgrade to version 2.4.67, which fixes the issue.
CVE-2025-23048CVSS 9.1In some mod_ssl configurations on Apache HTTP Server 2.4.35 through to 2.4.63, an access control bypass by trusted clients is possible using TLS 1.3 session resumption. Configurations are affected when mod_ssl is configured for multiple virtual hosts, with each restricted to a different set of trusted client certificates (for example with a different SSLCACertificateFile/Path setting). In such a case, a client trusted to access one virtual host may be able to access another virtual host, if SSLStrictSNIVHostCheck is not enabled in either virtual host.
CVE-2024-38475CVSS 9.1Improper escaping of output in mod_rewrite in Apache HTTP Server 2.4.59 and earlier allows an attacker to map URLs to filesystem locations that are permitted to be served by the server but are not intentionally/directly reachable by any URL, resulting in code execution or source code disclosure. Substitutions in server context that use a backreferences or variables as the first segment of the substitution are affected.  Some unsafe RewiteRules will be broken by this change and the rewrite flag "UnsafePrefixStat" can be used to opt back in once ensuring the substitution is appropriately constrained.

References

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