CVE-2020-25674 : Exploit Details and Defense Strategies
Learn about CVE-2020-25674, a vulnerability in ImageMagick that can lead to a heap-buffer-overflow due to an improper exit condition in the PNG coder, impacting application availability. Find out how to mitigate and prevent exploitation.
CVE-2020-25674 is a vulnerability in ImageMagick that can lead to a heap-buffer-overflow due to an improper exit condition in the PNG coder. This flaw could be exploited by processing a specially crafted input file, impacting application availability.
Understanding CVE-2020-25674
ImageMagick's WriteOnePNGImage() function in coders/png.c is susceptible to a heap-buffer-overflow vulnerability.
What is CVE-2020-25674?
The vulnerability arises from a for loop with an incorrect exit condition, potentially allowing an out-of-bounds READ via heap-buffer-overflow. The issue occurs when the colormap contains fewer than 256 valid values, but the loop condition iterates 256 times, leading to passing invalid colormap data to the event logger.
The Impact of CVE-2020-25674
Exploiting this vulnerability could result in a denial of service or arbitrary code execution when processing maliciously crafted files using ImageMagick versions prior to 7.0.8-68.
Technical Details of CVE-2020-25674
The technical aspects of the vulnerability in ImageMagick.
Vulnerability Description
The flaw in WriteOnePNGImage() function allows for a heap-buffer-overflow due to an incorrect loop exit condition, potentially leading to out-of-bounds READ.
Affected Systems and Versions
- Vendor: n/a
- Product: ImageMagick
- Affected Versions: prior to 7.0.8-68
Exploitation Mechanism
The vulnerability can be exploited by processing a specially crafted input file that triggers the improper exit condition in the PNG coder, leading to a heap-buffer-overflow.
Mitigation and Prevention
Measures to mitigate and prevent the exploitation of CVE-2020-25674.
Immediate Steps to Take
- Update ImageMagick to version 7.0.8-68 or later to patch the vulnerability.
- Avoid processing untrusted or unknown image files using ImageMagick.
Long-Term Security Practices
- Regularly update software and apply security patches promptly.
- Implement file type and content validation mechanisms to prevent processing of malicious files.
Patching and Updates
Ensure timely installation of security updates and patches provided by ImageMagick to address CVE-2020-25674.