CVE-2019-6977 : Vulnerability Insights and Analysis
Learn about CVE-2019-6977, a heap-based buffer overflow vulnerability in GD Graphics Library and PHP versions. Find out the impact, affected systems, exploitation mechanism, and mitigation steps.
A heap-based buffer overflow vulnerability exists in the gdImageColorMatch function within the GD Graphics Library (LibGD) version 2.2.5. This vulnerability is also present in the imagecolormatch function in PHP versions prior to 5.6.40, 7.x before 7.1.26, 7.2.x before 7.2.14, and 7.3.x before 7.3.1. An attacker with the ability to initiate imagecolormatch calls using manipulated image data can exploit this vulnerability.
Understanding CVE-2019-6977
This CVE involves a heap-based buffer overflow vulnerability in the GD Graphics Library and PHP versions.
What is CVE-2019-6977?
gdImageColorMatch in gd_color_match.c in the GD Graphics Library (aka LibGD) 2.2.5, as used in the imagecolormatch function in PHP before 5.6.40, 7.x before 7.1.26, 7.2.x before 7.2.14, and 7.3.x before 7.3.1, has a heap-based buffer overflow. This can be exploited by an attacker who is able to trigger imagecolormatch calls with crafted image data.
The Impact of CVE-2019-6977
- Affects GD Graphics Library and PHP versions prior to specified versions
- Allows an attacker to trigger imagecolormatch calls with manipulated image data
Technical Details of CVE-2019-6977
This section provides detailed technical information about the vulnerability.
Vulnerability Description
The vulnerability is a heap-based buffer overflow in the gdImageColorMatch function within the GD Graphics Library and the imagecolormatch function in PHP versions.
Affected Systems and Versions
- GD Graphics Library version 2.2.5
- PHP versions before 5.6.40, 7.x before 7.1.26, 7.2.x before 7.2.14, and 7.3.x before 7.3.1
Exploitation Mechanism
An attacker can exploit this vulnerability by initiating imagecolormatch calls with manipulated image data.
Mitigation and Prevention
Protecting systems from CVE-2019-6977 requires immediate actions and long-term security practices.
Immediate Steps to Take
- Apply patches provided by the respective vendors
- Monitor for any unusual imagecolormatch function calls
- Implement strict input validation for image data
Long-Term Security Practices
- Regularly update software and libraries to patched versions
- Conduct security audits to identify and mitigate similar vulnerabilities
Patching and Updates
- Refer to vendor advisories for specific patching instructions and updates