CVE-2012-1823 — PHP-CGI Query String Parameter Vulnerability
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.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- Confirmed exploitation (CISA KEV)+35
- Public exploit/PoC (nuclei, metasploit, exploitdb)+20
- EPSS 100% (30-day exploitation probability)+15
- Technical severity (critical)+10
- Automatable exploitation (SSVC)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — www.php.net (NIST National Vulnerability Database)
- Documented patch — bugs.php.net (NIST National Vulnerability Database)
- Documented patch — bugs.php.net (NIST National Vulnerability Database)
CISA required action CISA
Apply updates per vendor instructions.
US federal deadline: Apr 15, 2022 — passed 1644 day(s) ago
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Apple Mac Os X, Debian Debian Linux, Fedoraproject Fedora…).
- Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- Apply the fixed version or the patch documented under Remediation.
- EPSS ahead of 100% of scored CVEs: prioritize it in the patch queue.
- Search available logs for exploit probes matching the vulnerability class (injection), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Apple | Mac Os X | ≥ 10.8.0 and < 10.8.2≥ 10.6.8 and < 10.7.5 | Vulnerable | NIST National Vulnerability Database |
| Debian | Debian Linux | version 6.0 | Vulnerable | NIST National Vulnerability Database |
| Fedoraproject | Fedora | version 40version 39 | Vulnerable | NIST National Vulnerability Database |
| Hp | Hp-ux | version b.11.23version b.11.31 | Vulnerable | NIST National Vulnerability Database |
| Opensuse | Opensuse | version 11.4version 12.1 | Vulnerable | NIST National Vulnerability Database |
| Php | Php | < 5.3.12≥ 5.4.0 and < 5.4.2 | Vulnerable | NIST National Vulnerability Database |
| Red Hat | Application Stack | version 2.0 | Vulnerable | NIST National Vulnerability Database |
| Red Hat | Enterprise Linux Desktop | version 6.0 | Vulnerable | NIST National Vulnerability Database |
| Red Hat | Enterprise Linux Eus | version 5.6version 6.2version 6.1 | Vulnerable | NIST National Vulnerability Database |
| Red Hat | Enterprise Linux Server | version 5.0version 6.0 | Vulnerable | NIST National Vulnerability Database |
| Red Hat | Enterprise Linux Server Aus | version 5.3version 5.6 | Vulnerable | NIST National Vulnerability Database |
| Red Hat | Enterprise Linux Workstation | version 5.0version 6.0 | Vulnerable | NIST National Vulnerability Database |
| Red Hat | Gluster Storage Server For On-premise | version 2.0 | Vulnerable | NIST National Vulnerability Database |
| Red Hat | Storage | version 2.0 | Vulnerable | NIST National Vulnerability Database |
| Red Hat | Storage For Public Cloud | version 2.0 | Vulnerable | NIST National Vulnerability Database |
| SUSE | Linux Enterprise Server | version 11-sp2version 10-sp4 | Vulnerable | NIST National Vulnerability Database |
| SUSE | Linux Enterprise Software Development Kit | version 11-sp2version 10-sp4 | Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 9.8 | CVSS 3.1 | Critical | 3.9 | 5.9 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 via NIST National Vulnerability Database |
| 9.8 | CVSS 3.1 | Critical | — | — | CISA-ADP via CVE Program (cve.org) e CISA ADP |
| 7.5 | CVSS 2.0 | High | 10.0 | 6.4 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: 134c704f-9b21-4f2e-91b3-4a467353bcc0) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
CISA KEV details CISA
CISA lists a CVE once it has evidence of exploitation against real targets.
CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a reference date.
Public exploits, PoCs and detection templates
Public code that demonstrates or tests the flaw raises the odds of mass exploitation — and Nuclei templates help find vulnerable assets in your environment.
- PHP CGI Argument Injection excellent May 3, 2012
- PHP 5.3.12/5.4.2 - CGI Argument Injection (Metasploit) verified May 4, 2012
- PHP < 5.3.12 / < 5.4.2 - CGI Argument Injection verified May 5, 2012
- Apache + PHP < 5.3.12 / < 5.4.2 - cgi-bin Remote Code Execution verified Oct 29, 2013
- Apache + PHP < 5.3.12 / < 5.4.2 - Remote Code Execution + Scanner Oct 31, 2013
Warning: public PoCs are sometimes disguised malware. Use them only for authorized testing in an isolated environment. This portal does not host exploit code — it only points to the sources.
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 100.00%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Look for parameters with command/query metacharacters and unexpected child processes of the service.
- Hunt retroactively in logs from before Mar 25, 2022 (KEV listing): exploitation may have started earlier.
Timeline
What happened to this CVE, newest first.
- 2026
- SSVC assessment updated
- Record published
- Fix documented
- Affected products added · php/php, fedoraproject/fedora, debian/debian linux, hp/hp-ux, opensuse/opensuse, suse/linux enterprise server, suse/linu
- CVSS changed · 9.8
- Source status changed · → Analyzed
- Added to CISA KEV (detected)
- Record created in this database
- 2022
- Added to CISA KEV catalog
- 2012
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× References added · Oct 13, 2026 – Oct 13, 2026
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
31 on the record
- bugs.php.net/patch-display.php
- bugs.php.net/bug.php
- www.php.net/ChangeLog-5.php
- www.cisa.gov/known-exploited-vulnerabilities-catalog
- rhn.redhat.com/errata/RHSA-2012-0547.html
- lists.opensuse.org/opensuse-security-announce/2012-05/msg00007.html
- www.php.net/archive/2012.php
- lists.apple.com/archives/security-announce/2012/Sep/msg00004.html
- secunia.com/advisories/49065
- www.mandriva.com/security/advisories
- marc.info/
- rhn.redhat.com/errata/RHSA-2012-0569.html
- secunia.com/advisories/49087
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/W45D
- secunia.com/advisories/49085
- rhn.redhat.com/errata/RHSA-2012-0568.html
- www.kb.cert.org/vuls/id/520827
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PKGTQU
- support.apple.com/kb/HT5501
- lists.opensuse.org/opensuse-security-announce/2012-05/msg00011.html
- secunia.com/advisories/49014
- www.openwall.com/lists/oss-security/2024/06/07/1
- lists.opensuse.org/opensuse-security-announce/2012-05/msg00002.html
- www.kb.cert.org/vuls/id/673343
- eindbazen.net/2012/05/php-cgi-advisory-cve-2012-1823/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PKGT
- h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp
- rhn.redhat.com/errata/RHSA-2012-0546.html
- www.securitytracker.com/id
- www.debian.org/security/2012/dsa-2465
- rhn.redhat.com/errata/RHSA-2012-0570.html
Elsewhere on this site
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Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2012-1823 is "PHP-CGI Query String Parameter Vulnerability", rated Critical. It affects Mac Os X (Apple); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 9.8 describes technical severity. EPSS 100.00% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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