In PHP versions prior to 7.4.33, 8.0.25, and 8.1.12, when using the imageloadfont() function in the gd extension, it is possible to supply a specially crafted font file. If the loaded font is used with the imagechar() function, it can lead to reading outside the allocated buffer. This vulnerability allows for potential crashes or the disclosure of confidential information.
The severity of this vulnerability is rated as medium with a CVSS score of 6.5. This indicates that while the likelihood of exploitation is moderate, the potential impact can be significant, especially in environments where PHP is widely used.
Risk to organizations includes potential exposure of sensitive data, system crashes, and disruption of services. Attackers may leverage this vulnerability to perform unauthorized actions on affected systems, which necessitates urgent attention.
Organizations should prioritize patching immediately. Updating to the latest versions of PHP is essential to mitigate this risk and ensure the integrity of applications relying on this language.
Vulnerability Details
The official description of the vulnerability indicates that it arises from insufficient input validation when handling font files in the gd extension. The CVE-2022-31630 affects PHP versions prior to 7.4.33, 8.0.25, and 8.1.12, with a CVSS score of 6.5, reflecting a medium severity.
Technical Analysis
The root cause of the vulnerability lies in the way the imageloadfont() function processes font files. It allows specially crafted files that can lead to out-of-bounds reads, exposing sensitive data or causing application crashes.
The attack vector is network-based, requiring no user interaction and minimal privileges, making it easier for attackers to exploit vulnerable systems remotely.
Risk & Impact Analysis
The risk associated with this vulnerability is particularly relevant for organizations utilizing PHP in web applications. Given the wide deployment of PHP, the potential blast radius is significant. Exploitation can lead to unauthorized access to data or service interruptions.
With a medium severity rating and an exploitability score indicating a moderate risk, organizations should address this vulnerability in their patch management cycle. Regular updates and security reviews are essential to protect against such vulnerabilities.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | Yes |
Public PoC | Yes |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The affected versions include PHP versions prior to 7.4.33, 8.0.25, and 8.1.12. Organizations running any of these versions are strongly advised to upgrade to the latest stable release.
Mitigation & Remediation
To mitigate this vulnerability, organizations should apply the latest patches provided by PHP. For those unable to update immediately, consider implementing additional security measures such as restricting access to the gd extension and monitoring for unusual behavior.
Detection Guidance
Monitoring logs for unusual access patterns or error messages related to the gd extension can help in early detection of exploitation attempts.
AppSecure Threat Intelligence Insight
This vulnerability highlights the importance of rigorous input validation in software development. Security teams should focus on implementing robust validation mechanisms to prevent similar vulnerabilities from arising in the future.
Organizations are encouraged to adopt a proactive approach in vulnerability management by regularly reviewing and updating their security practices.
For further insights into securing PHP applications, consider exploring our resources on application security assessment and penetration testing methodology to identify gaps in your security posture.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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