CVE-2017-12676 in ImageMagick
Summary
by MITRE
In ImageMagick 7.0.6-3, a memory leak vulnerability was found in the function ReadOneJNGImage in coders/png.c, which allows attackers to cause a denial of service.
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Analysis
by VulDB Data Team • 12/15/2022
The vulnerability identified as CVE-2017-12676 represents a critical memory leak flaw within ImageMagick's handling of JNG (JPEG Network Graphics) image files. This issue specifically affects ImageMagick version 7.0.6-3 and stems from improper memory management within the ReadOneJNGImage function located in the coders/png.c source file. The flaw manifests when processing maliciously crafted JNG files that contain malformed data structures, leading to memory allocation without subsequent deallocation, which creates a progressive memory consumption pattern that can exhaust available system resources.
The technical implementation of this vulnerability involves the failure to properly release allocated memory blocks during the image parsing process. When ImageMagick encounters a JNG file with specific characteristics, the ReadOneJNGImage function allocates memory for various image components but fails to execute proper cleanup routines when encountering certain error conditions or malformed data sequences. This memory leak occurs in the context of image format parsing where the application attempts to decode progressive JPEG data within the JNG container format, creating a scenario where allocated memory becomes unreachable but not freed, resulting in gradual memory exhaustion.
From an operational impact perspective, this vulnerability enables attackers to execute successful denial of service attacks against systems running vulnerable versions of ImageMagick. The memory leak can be exploited through simple file upload mechanisms or by processing JNG files in web applications that utilize ImageMagick for image handling. Attackers can repeatedly submit malicious JNG files to consume system memory resources, potentially causing system instability, application crashes, or complete system hangs. The vulnerability is particularly dangerous in web environments where ImageMagick is used for automatic image processing, as it can be triggered through automated attacks without requiring user interaction.
The exploitability of this vulnerability aligns with common attack patterns found in software security vulnerabilities, particularly those classified under CWE-401, which addresses improper management of dynamic memory allocation. This weakness falls within the broader category of memory management flaws that can be leveraged for denial of service attacks, making it a significant concern for systems that process untrusted image files. The vulnerability's impact is further amplified by the widespread adoption of ImageMagick across various platforms and applications, including web servers, content management systems, and image processing pipelines that may not implement proper input validation or resource monitoring.
Organizations should implement immediate mitigations including updating to patched versions of ImageMagick where available, implementing strict input validation for image file types, and deploying resource monitoring to detect abnormal memory consumption patterns. Network-based protections such as content filtering and sandboxing mechanisms can provide additional layers of defense. The ATT&CK framework categorizes this vulnerability under the T1499.004 technique for Network Denial of Service, emphasizing the importance of proper resource management and input validation in preventing such attacks. Regular security assessments and vulnerability scanning should be conducted to identify systems running vulnerable versions of ImageMagick and ensure timely patch deployment.