CVE-2017-12428 in ImageMagick
Summary
by MITRE
In ImageMagick 7.0.6-1, a memory leak vulnerability was found in the function ReadWMFImage in coders/wmf.c, which allows attackers to cause a denial of service in CloneDrawInfo in draw.c.
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Analysis
by VulDB Data Team • 12/14/2022
The vulnerability identified as CVE-2017-12428 represents a critical memory leak flaw within ImageMagick's handling of Windows Metafile (WMF) image formats. This issue specifically affects ImageMagick version 7.0.6-1 and manifests within the ReadWMFImage function located in the coders/wmf.c source file. The memory leak occurs during the processing of WMF image files, where the software fails to properly release allocated memory resources after completing the image parsing operations. This improper memory management creates a condition where repeated processing of WMF files can gradually consume system resources until the application or system becomes unresponsive.
The technical exploitation of this vulnerability occurs through the manipulation of WMF image files that are processed by ImageMagick's image handling pipeline. When the ReadWMFImage function encounters a specially crafted WMF file, it allocates memory to store intermediate image data structures but fails to properly deallocate this memory upon function completion. The subsequent call to CloneDrawInfo in draw.c perpetuates this memory leak condition, as the cloned drawing information structures maintain references to the previously allocated but unreleased memory segments. This creates a cascading effect where each processed WMF file contributes to progressive memory consumption without proper garbage collection.
The operational impact of this memory leak vulnerability extends beyond simple resource exhaustion, creating significant denial of service conditions that can affect systems relying on ImageMagick for image processing tasks. Attackers can exploit this vulnerability by submitting malicious WMF files to applications that utilize ImageMagick for image conversion or processing, leading to gradual system performance degradation or complete application crashes. The vulnerability is particularly concerning in web applications or services that accept user-uploaded images, as it allows for sustained resource exhaustion attacks that can render the service unavailable to legitimate users. This type of vulnerability aligns with CWE-401, which specifically addresses memory leaks in software applications, and represents a classic example of insufficient resource management that can be exploited for denial of service attacks.
Organizations utilizing ImageMagick should implement immediate mitigations to address this vulnerability, including updating to patched versions of ImageMagick that contain proper memory deallocation routines in the WMF processing code. The recommended approach involves applying the vendor-supplied security patches that correct the memory leak in ReadWMFImage and ensure proper cleanup of allocated resources during the image processing workflow. Additionally, implementing input validation and file type restriction measures can provide defense-in-depth protection by preventing the processing of untrusted WMF files or limiting the number of image processing operations that can be performed within a given time frame. These mitigations align with ATT&CK technique T1499.004, which addresses resource exhaustion attacks through memory leaks and improper resource management. System administrators should also consider implementing monitoring solutions that can detect unusual memory consumption patterns and alert on potential exploitation attempts, as this vulnerability can be used in automated attack scenarios targeting web applications and image processing services.