CVE-2012-3437 in ImageMagick
Summary
by MITRE
The Magick_png_malloc function in coders/png.c in ImageMagick 6.7.8 and earlier 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-2012-3437 represents a critical memory allocation flaw within ImageMagick's PNG handling subsystem. This issue resides in the Magick_png_malloc function located in the coders/png.c source file of ImageMagick versions 6.7.8 and earlier. The flaw stems from improper variable type usage during memory allocation operations, creating a scenario where maliciously crafted PNG files can trigger unexpected behavior in the application's memory management system. The vulnerability specifically affects the allocation size parameter, which when incorrectly typed can lead to arithmetic overflow conditions or invalid memory operations that ultimately result in application instability.
The technical implementation of this vulnerability exploits a type confusion issue where the function fails to properly handle the size parameter during memory allocation requests. When processing specially crafted PNG files, the incorrect variable typing causes the allocation logic to compute erroneous memory sizes, potentially leading to heap corruption or allocation failures that manifest as application crashes. This type of flaw falls under the CWE-190 category of integer overflow and under CWE-787 for out-of-bounds write conditions, representing a fundamental memory safety issue. The vulnerability demonstrates how seemingly minor type declaration errors in low-level memory management functions can create significant security implications for applications processing untrusted binary data.
From an operational perspective, this vulnerability creates a reliable denial of service condition that remote attackers can exploit by simply presenting a malicious PNG file to any application using vulnerable ImageMagick versions. The impact extends beyond simple service disruption as it can affect web applications, content management systems, and any platform that processes user-uploaded images through ImageMagick. The attack vector is particularly dangerous because PNG files are widely used and trusted formats, making them ideal for social engineering attacks where attackers can convince users to upload or view seemingly harmless images that trigger the vulnerability. This flaw directly maps to ATT&CK technique T1203 for exploitation for privilege escalation and T1499 for network denial of service, as it can be leveraged to disrupt services without requiring authentication or elevated privileges.
The mitigation strategies for CVE-2012-3437 primarily involve immediate version upgrades to ImageMagick 6.7.9 or later, where the memory allocation handling has been corrected to use proper variable types for allocation sizes. System administrators should also implement input validation measures that restrict image file types and sizes, along with deploying web application firewalls that can detect and block suspicious image file patterns. Additional protective measures include running ImageMagick in restricted environments with limited memory allocation capabilities and implementing proper error handling that prevents crash propagation. Organizations should also consider using alternative image processing libraries that have been more thoroughly vetted for memory safety issues, as well as establishing comprehensive monitoring systems to detect potential exploitation attempts through unusual memory allocation patterns or process crash events.