CVE-2017-12666 in ImageMagick
Summary
by MITRE
ImageMagick 7.0.6-2 has a memory leak vulnerability in WriteINLINEImage in coders/inline.c.
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Analysis
by VulDB Data Team • 03/05/2025
The vulnerability identified as CVE-2017-12666 represents a critical memory leak flaw within ImageMagick version 7.0.6-2, specifically affecting the WriteINLINEImage function located in the coders/inline.c source file. This issue manifests when the software processes certain image formats that utilize inline data handling mechanisms, creating a scenario where allocated memory resources are not properly released back to the system. The memory leak occurs during the image writing process when inline image data is being processed, leading to gradual memory consumption that can ultimately impact system stability and performance. This vulnerability falls under the broader category of memory management flaws that can be exploited to cause denial of service conditions or resource exhaustion attacks.
The technical implementation of this vulnerability stems from improper memory deallocation within the WriteINLINEImage function which handles inline image data processing. When ImageMagick encounters an image file that requires inline data handling, the software allocates memory buffers to store temporary image information during the write operation. However, due to a flaw in the memory management logic, these allocated memory blocks are not consistently freed when the processing completes, resulting in memory fragmentation and progressive resource consumption. The vulnerability is particularly concerning because it occurs during legitimate image processing operations, making it difficult to distinguish between normal usage and exploitation attempts. This memory leak vulnerability can be classified as a CWE-401: Improper Release of Memory Before Removing Last Reference, which is a well-documented weakness in memory management practices.
The operational impact of CVE-2017-12666 extends beyond simple resource consumption, as it can be leveraged to create persistent denial of service conditions within systems that rely on ImageMagick for image processing tasks. When exploited, this vulnerability can cause applications using ImageMagick to gradually consume all available memory, leading to system instability, application crashes, or complete system hangs. The vulnerability is particularly dangerous in server environments where ImageMagick is used to process user-uploaded images, as malicious actors could repeatedly submit specially crafted image files to exhaust system resources. This type of attack aligns with ATT&CK technique T1499.004: Endpoint Denial of Service, where adversaries target resource exhaustion to disrupt system operations. The memory leak can also compound other security issues, as systems under memory pressure may exhibit unpredictable behavior that could be exploited for additional attacks.
Mitigation strategies for CVE-2017-12666 should prioritize immediate patching of affected ImageMagick installations to version 7.0.6-3 or later, which contains the necessary memory management fixes. Organizations should implement proper input validation and sanitization for all image processing operations, particularly when handling untrusted user uploads. Network segmentation and access controls can help limit the potential impact of exploitation by restricting access to systems running ImageMagick. Additionally, implementing memory monitoring and alerting systems can help detect abnormal memory consumption patterns that may indicate exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to identify other potential memory management issues within the software ecosystem. The fix implemented in the patched version addresses the core memory deallocation issue by ensuring proper cleanup of allocated resources during inline image processing operations, thereby preventing the accumulation of unreleased memory blocks that characterized the original vulnerability.