CVE-2017-13142 in ImageMagick
Summary
by MITRE
In ImageMagick before 6.9.9-0 and 7.x before 7.0.6-1, a crafted PNG file could trigger a crash because there was an insufficient check for short files.
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Analysis
by VulDB Data Team • 12/16/2022
The vulnerability identified as CVE-2017-13142 represents a critical buffer over-read condition within ImageMagick's PNG file processing functionality. This flaw exists in versions prior to 6.9.9-0 and 7.x prior to 7.0.6-1, where the software fails to adequately validate the length of incoming PNG files before attempting to parse their contents. The insufficient file length checking creates a scenario where maliciously crafted PNG files can cause the application to access memory beyond the allocated buffer boundaries, resulting in an application crash or potential code execution. This vulnerability falls under the CWE-129 category of Improper Validation of Array Index, specifically manifesting as an insufficient check for short files during image processing operations.
The technical exploitation of this vulnerability occurs when ImageMagick attempts to process a malformed PNG file that contains fewer bytes than expected by the parser. During the parsing sequence, the software reads header information and assumes certain minimum file sizes to accommodate specific data structures. When a crafted file violates these assumptions, the parser continues to read beyond the valid file boundaries, causing memory corruption that ultimately leads to a segmentation fault or application termination. This type of vulnerability is particularly dangerous because it can be triggered through automated processing of user-uploaded content, making it a prime target for remote code execution attacks when ImageMagick is used in web applications or file processing services.
The operational impact of CVE-2017-13142 extends beyond simple application crashes to potentially enable more sophisticated attack vectors. When exploited in web environments where ImageMagick processes user uploads, attackers can leverage this vulnerability to cause denial of service or potentially execute arbitrary code on affected systems. The vulnerability is particularly concerning in contexts such as content management systems, image processing APIs, and web applications that automatically convert or resize uploaded images. According to ATT&CK framework category T1203, this vulnerability could be classified as a process injection technique where the crash behavior might be exploited to trigger additional system instability or be combined with other vulnerabilities to achieve more significant compromise. The vulnerability's exploitation is relatively straightforward since it only requires crafting a specific type of malformed PNG file, making it accessible to attackers with basic knowledge of file format structures.
Mitigation strategies for CVE-2017-13142 primarily involve upgrading to patched versions of ImageMagick where the file validation has been strengthened. Organizations should ensure their ImageMagick installations are updated to version 6.9.9-0 or later, or version 7.0.6-1 or later for the 7.x series. Additionally, implementing proper input validation at the application level can provide defense-in-depth measures, including verifying file signatures before processing and limiting the maximum file size that can be processed. Network-level protections such as content filtering and sandboxing image processing operations can further reduce the risk exposure. Security monitoring should be implemented to detect unusual processing patterns that might indicate exploitation attempts, particularly when processing files from untrusted sources. The vulnerability demonstrates the importance of proper bounds checking and input validation in image processing libraries, aligning with security best practices outlined in the OWASP Top Ten and NIST cybersecurity guidelines for preventing buffer overflows and memory corruption vulnerabilities.