CyberSecBulletin
CVE-2024-8927NVD status: Modified

PHP: Insufficient Granularity of Access Control

Published Updated By the CyberSecBulletin desk

CVE-2024-8927 is a high-severity insufficient granularity of access control vulnerability in PHP from PHP Group, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 8.1.30, 8.2.24, 8.3.12 as the first without the flaw, so updating PHP to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.05% chance of exploitation within 30 days, higher than 65% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update PHP to 8.1.30 or 8.2.24 or 8.3.12, whichever matches your release line, or a later version.
  2. Update php to 8.1.30 or 8.2.24 or 8.3.12, whichever matches your release line, or a later version.
  3. Read the advisory on github.com for workarounds and exact fixed builds.
  4. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
PHP GroupPHP8.1.* up to, but not including, 8.1.30; 8.2.* up to, but not including, 8.2.24; 8.3.* up to, but not including, 8.3.128.1.30, 8.2.24, 8.3.12
PHPphp8.1.0 up to, but not including, 8.1.30; 8.2.0 up to, but not including, 8.2.24; 8.3.0 up to, but not including, 8.3.128.1.30, 8.2.24, 8.3.12

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
NoneNothing can be modified.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.5HighCNA (php.net)
CVSS 3.17.5HighNVD

Official description

In PHP versions 8.1.* before 8.1.30, 8.2.* before 8.2.24, 8.3.* before 8.3.12, HTTP_REDIRECT_STATUS variable is used to check whether or not CGI binary is being run by the HTTP server. However, in certain scenarios, the content of this variable can be controlled by the request submitter via HTTP headers, which can lead to cgi.force_redirect option not being correctly applied. In certain configurations this may lead to arbitrary file inclusion in PHP.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Insufficient Granularity of Access Control

The product implements access controls via a policy or other feature with the intention to disable or restrict accesses (reads and/or writes) to assets in a system from untrusted agents. However, implemented access controls lack the required granularity

How developers prevent this class of flaw

  • Access-control-policy protections must be reviewed for design inconsistency and common weaknesses. Access-control-policy definition and programming flow must be tested in pre-silicon, post-silicon testing.

More Insufficient Granularity of Access Control vulnerabilities (CWE-1220)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in PHP

All PHP vulnerabilities

Recent Insufficient Granularity of Access Control vulnerabilities

Spotted an error? Tell us.