How severe is CVE-2012-1823?

CVE-2012-1823 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2012-1823?

Affected package information for CVE-2012-1823 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2012-1823?

No fixed version has been published for CVE-2012-1823 yet. Monitor the advisory for updates, apply mitigations recommended by the vendor, and use O3 Security to track when a fix becomes available in your stack.

Is CVE-2012-1823 actively exploited in the wild?

Yes. There are 18 known exploit references for CVE-2012-1823, including 4 documented proof-of-concept exploits on Exploit-DB and 11 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2012-1823?

CVE-2012-1823 has an EPSS (Exploit Prediction Scoring System) score of 94.4%, placing it in the 100th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2012-1823 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2012-1823 (PHP-CGI Query String Parameter Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2022-03-25. CISA required all US federal civilian agencies to remediate this vulnerability by 2022-04-15. The required action was: Apply updates per vendor instructions. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2012-1823?

CVE-2012-1823 is classified as CWE-77 (CWE-77). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

Which products and versions are affected by CVE-2012-1823?

CVE-2012-1823 affects apple mac os x; debian debian linux (1 version, e.g. 6.0); fedoraproject fedora (2 versions, e.g. 39, 40); hp hp-ux (2 versions, e.g. b.11.23, b.11.31), and 13 more product(s). Check the affected-products list on this page against your deployed version to confirm exposure.

Is there exploit tooling available for CVE-2012-1823?

A Nuclei detection template exists for CVE-2012-1823, meaning automated scanners can fingerprint it. Public exploit tooling significantly increases real-world risk — prioritize patching and ensure detection coverage. Exploit tooling should only ever be used in isolated, authorized testing environments.

When was CVE-2012-1823 published, and has it been updated?

CVE-2012-1823 was published on May 11, 2012 and was last updated on April 21, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CISA KEV·Added 2022-03-25 — agencies required to remediate by 2022-04-15

CVE-2012-1823

CRITICAL

sapi/cgi/cgi_main.c in PHP before 5.3.12 and 5.4.x before 5.4.2, when configured as a CGI script (aka php-cgi), does not properly handle query strings that lack an = (equals sign) character,…

Published

May 11, 2012

Updated

Apr 21, 2026

Affected

0 pkgs

Patched

None yet

Exploits

18 known

EPSS Exploitation Probability

via FIRST.org ↗

94.4%probability of exploitation in next 30 days

Very High Risk100th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Description

sapi/cgi/cgi_main.c in PHP before 5.3.12 and 5.4.x before 5.4.2, when configured as a CGI script (aka php-cgi), does not properly handle query strings that lack an = (equals sign) character, which allows remote attackers to execute arbitrary code by placing command-line options in the query string, related to lack of skipping a certain php_getopt for the 'd' case.

Affected Products

17 products · 30 configurations

mac os xapple

≥ 10.8.0 && < 10.8.2

range

debian linuxdebian

1 version

6.0

fedorafedoraproject

2 versions

3940

hp-uxhp

2 versions

b.11.23b.11.31

opensuseopensuse

2 versions

11.412.1

Application

phpphp

≥ 5.4.0 && < 5.4.2

range

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

EDB-29290remotephp✓ Verified

Apache + PHP < 5.3.12 / < 5.4.2 - cgi-bin Remote Code Execution

by kingcope · Oct 29, 2013

Exploit-DB Source

EDB-18836remotephp✓ Verified

PHP < 5.3.12 / < 5.4.2 - CGI Argument Injection

by rayh4c · May 5, 2012

Exploit-DB Source

EDB-29316remotephp

Apache + PHP < 5.3.12 / < 5.4.2 - Remote Code Execution + Scanner

by noptrix · Oct 31, 2013

Exploit-DB Source

EDB-18834remotephp✓ Verified

PHP 5.3.12/5.4.2 - CGI Argument Injection (Metasploit)

by Metasploit · May 4, 2012

Exploit-DB Source

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2012-1823 in your stack?

O3 detects CVE-2012-1823 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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