PHP: Improper Neutralization of Special Elements in Output Used by a Downstream Component
CVE-2024-11234 is a high-severity improper neutralization of special elements in output used by a downstream component vulnerability in PHP from PHP Group, with a CVSS 3.1 base score of 7.2 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 8.1.31, 8.2.26, 8.3.14 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 1.11% chance of exploitation within 30 days, higher than 66% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update PHP to 8.1.31 or 8.2.26 or 8.3.14, whichever matches your release line, or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| PHP Group | PHP | 8.1.* up to, but not including, 8.1.31; 8.2.* up to, but not including, 8.2.26; 8.3.* up to, but not including, 8.3.14; 8.1.0 up to, but not including, 8.1.31; 8.2.0 up to, but not including, 8.2.26; 8.3.0 up to, but not including, 8.3.14 | 8.1.31, 8.2.26, 8.3.14 |
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
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- LowSome restricted data can be read.
- Integrity
- LowLimited modification of data is possible.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 4.8 | Medium | CNA (php.net) |
| CVSS 3.1 | 7.2 | High | NVD |
Official description
In PHP versions 8.1.* before 8.1.31, 8.2.* before 8.2.26, 8.3.* before 8.3.14, when using streams with configured proxy and "request_fulluri" option, the URI is not properly sanitized which can lead to HTTP request smuggling and allow the attacker to use the proxy to perform arbitrary HTTP requests originating from the server, thus potentially gaining access to resources not normally available to the external user.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Special Elements in Output Used by a Downstream Component
The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.
How developers prevent this class of flaw
- Programming languages and supporting technologies might be chosen which are not subject to these issues.
- Utilize an appropriate mix of allowlist and denylist parsing to filter control-plane syntax from all input.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- github.com/php/php-src/security/advisories/GHSA-c5f2-jwm7-mmq2Exploit, Third Party Advisory
Other references
Other vulnerabilities in PHP
- 8.1 High severity
PHP Stale Internal Request-State Exploited
- 9.8 Critical severity
PHP Memory Corruption Exploited
- 7.5 High severity
- 7.5 High severity
- 9.8 Critical severity
- 9.8 Critical severity
Recent Improper Neutralization of Special Elements in Output Used by a Downstream Component vulnerabilities
- 8.8 High severity
- 7.2 High severity
- 8.7 High severity
- 7.2 High severity
- 7.3 High severity
- 9.8 Critical severity
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