CVE-2012-3438 in GraphicsMagick
Summary
by MITRE
The Magick_png_malloc function in coders/png.c in GraphicsMagick 6.7.8-6 does not use the proper variable type for the allocation size, which might allow remote attackers to cause a denial of service (crash) via a crafted PNG file that triggers incorrect memory allocation.
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Analysis
by VulDB Data Team • 12/31/2024
The vulnerability identified as CVE-2012-3438 resides within the GraphicsMagick library's handling of png image files, specifically in the Magick_png_malloc function located in coders/png.c. This flaw represents a classic memory management error that occurs when the allocation size parameter is not properly typed during memory allocation operations. GraphicsMagick, a robust image processing library, processes various image formats including png files, making this vulnerability particularly concerning for systems that process untrusted image content. The improper variable type handling in the allocation size parameter creates a scenario where the memory allocator receives incorrect sizing information, potentially leading to memory corruption or allocation failures.
The technical nature of this vulnerability stems from type confusion within the memory allocation mechanism. When GraphicsMagick encounters a crafted png file, the Magick_png_malloc function processes the file's metadata and attempts to allocate memory based on calculated dimensions or other parameters. The improper variable type usage means that the size calculation or assignment may overflow or underflow, causing the malloc function to receive an invalid allocation size. This can manifest as either attempting to allocate zero bytes, which typically results in no memory being allocated, or allocating an excessively large amount of memory that could cause system instability. The vulnerability specifically targets the png image processing pipeline, making it exploitable through image upload or processing operations in web applications, content management systems, or any software that utilizes GraphicsMagick for image handling.
The operational impact of this vulnerability extends beyond simple denial of service to potentially compromise system stability and availability. Remote attackers can craft malicious png files that, when processed by vulnerable GraphicsMagick installations, trigger the memory allocation error and cause application crashes. This makes the vulnerability particularly dangerous in web applications where users can upload images, as it allows for automated exploitation without requiring user interaction beyond uploading the malicious file. The crash behavior can be leveraged in distributed denial of service attacks or to exhaust system resources, as repeated exploitation attempts can cause continuous application instability. This vulnerability aligns with CWE-129, which addresses improper validation of array indices, and represents a memory safety issue that affects the fundamental memory management operations within the library.
Systems utilizing GraphicsMagick 6.7.8-6 or earlier versions are at risk when processing untrusted png image files, particularly web applications, image processing services, or any software that accepts user-uploaded images. The vulnerability's exploitability is high due to the common usage of png format in web applications and the ease with which attackers can craft malicious files. Organizations should prioritize patching their GraphicsMagick installations to versions that address this memory allocation issue. Mitigation strategies include implementing strict input validation for image files, using sandboxed environments for image processing, and employing additional layers of security such as file type verification and size limits. The ATT&CK framework categorizes this vulnerability under privilege escalation and denial of service techniques, as it can be leveraged to disrupt services and potentially gain unauthorized access to system resources through application crashes and memory corruption. Security monitoring should include detection of unusual memory allocation patterns and application crashes during image processing operations to identify potential exploitation attempts.