CVE-2019-11926 Explained : Impact and Mitigation
Learn about CVE-2019-11926 affecting HHVM versions, allowing unauthorized memory access. Find out the impact, affected systems, exploitation method, and mitigation steps.
HHVM versions prior to 3.30.9 and between 4.0.0 to 4.20.1 are affected by a vulnerability in the GD extension that could lead to unauthorized memory access.
Understanding CVE-2019-11926
This CVE identifies a security vulnerability in HHVM versions that could be exploited to access memory beyond its bounds.
What is CVE-2019-11926?
The GD extension in HHVM versions exhibits insufficient boundary checks when processing M_SOFx markers from JPEG headers, allowing unauthorized memory access through specially crafted invalid JPEG input.
The Impact of CVE-2019-11926
This vulnerability could enable attackers to access memory beyond its bounds, potentially leading to unauthorized access to sensitive information or system compromise.
Technical Details of CVE-2019-11926
The technical aspects of the vulnerability are as follows:
Vulnerability Description
The GD extension in HHVM versions prior to 3.30.9 and between 4.0.0 to 4.20.1 lacks proper boundary checks when processing certain markers from JPEG headers, potentially leading to out-of-bounds memory access.
Affected Systems and Versions
- HHVM versions prior to 3.30.9
- HHVM versions between 4.0.0 and 4.20.1
Exploitation Mechanism
Attackers can exploit this vulnerability by providing specially crafted invalid JPEG input to the GD extension, triggering insufficient boundary checks and gaining unauthorized access to memory.
Mitigation and Prevention
To address CVE-2019-11926, consider the following mitigation strategies:
Immediate Steps to Take
- Apply patches provided by HHVM promptly
- Monitor security advisories for updates
- Implement network security measures to detect and block malicious activities
Long-Term Security Practices
- Regularly update HHVM to the latest secure versions
- Conduct security assessments and audits to identify vulnerabilities
- Educate developers on secure coding practices
Patching and Updates
- Facebook has released security updates to address this vulnerability
- Ensure timely installation of patches to protect systems from exploitation