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Weekly Signal
Live intelligence Updated 20 Aug 2026 · 01:51 UTC

Apple, Debian, Fedoraproject +5 more · Mac Os X, Debian Linux, Fedora +14 more

CVE-2012-1823

PHP-CGI Query String Parameter Vulnerability

Recommended action

Treat this as an immediate remediation priority. Apply updates per vendor instructions.

View response plan
CVSS9.8
EPSS100.0%
KEVYes
ExploitationConfirmed exploitation
PatchPatch or guidance available ↓

Assessment

Why it matters

CISA lists this vulnerability as known to be exploited; exploitation is confirmed; EPSS is 100.0%; technical severity is CVSS 9.8.

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 should care

  • Teams operating Mac Os X, Debian Linux, Fedora +14 more
  • Vulnerability and exposure management teams
  • Security operations teams monitoring exploitation activity

Response plan

What I would do

  1. Confirm whether Mac Os X, Debian Linux, Fedora +14 more is present in the environment.
  2. Identify affected versions and establish whether vulnerable services are exposed or reachable.
  3. Apply updates per vendor instructions.
  4. Review relevant security telemetry for evidence of attempted or successful exploitation.
  5. Document the remediation decision and track it to verified completion.

Vendor remediation

Patch and remediation links

Use the vendor source below to confirm the correct fixed version, package or mitigation for your affected product.

Technical details

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-20
Affected versions
Apple Mac Os X (Start Including: 10.8.0, End Excluding: 10.8.2); Debian Debian Linux (Version: 6.0); Fedoraproject Fedora (Version: 40); Hp Hp-ux (Version: b.11.31); Opensuse Opensuse (Version: 12.1); PHP PHP (Start Including: 5.4.0, End Excluding: 5.4.2); Redhat Application Stack (Version: 2.0); Redhat Enterprise Linux Desktop (Version: 6.0)
Published
11 May 2012
Attack vector
Network
Privileges required
None
User interaction
None

Signal timeline

  1. CVE published
  2. Added to CISA KEV
  3. Latest EPSS score: 100.0%
  4. Signal calculated at 85

External references

Live public intelligence This assessment combines public-source evidence. Validate the affected product, version and exposure against your own environment before making a risk decision.