CVE-2017-7942 in ImageMagick
Summary
by MITRE
The ReadAVSImage function in avs.c in ImageMagick 7.0.5-4 allows remote attackers to consume an amount of available memory via a crafted file.
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Analysis
by VulDB Data Team • 11/29/2022
The vulnerability identified as CVE-2017-7942 resides within the ReadAVSImage function of ImageMagick version 7.0.5-4, representing a critical memory consumption flaw that enables remote attackers to execute denial of service attacks through maliciously crafted image files. This issue falls under the category of memory corruption vulnerabilities and specifically manifests as a heap-based buffer overflow or excessive memory allocation during image processing operations. The flaw occurs when the application attempts to parse AVS ( Autodesk Visual Effects ) image files without proper input validation or memory allocation limits, allowing attackers to craft files that trigger disproportionate memory usage patterns.
The technical implementation of this vulnerability exploits the insufficient bounds checking and memory management within the AVS image parsing routine. When ImageMagick processes a specially crafted AVS file, the ReadAVSImage function fails to properly validate the file structure and allocate appropriate memory resources, leading to uncontrolled memory consumption that can exhaust system resources and potentially crash the application. This vulnerability is particularly dangerous because it operates at the image parsing layer where applications typically process untrusted input from external sources, making it a prime target for remote exploitation in web applications, file processing services, and content management systems that utilize ImageMagick for image handling.
From an operational perspective, this vulnerability presents significant risks to organizations relying on ImageMagick for image processing tasks, as it can be exploited to disrupt services through resource exhaustion attacks. The impact extends beyond simple denial of service to potentially enable more sophisticated attacks when combined with other vulnerabilities, as attackers can leverage the memory consumption to create conditions favorable for additional exploits. The vulnerability demonstrates a classic weakness in input validation and resource management practices that aligns with CWE-122, which describes heap-based buffer overflow conditions, and also relates to CWE-400, addressing unspecified resource exhaustion vulnerabilities. Attackers can exploit this flaw by uploading or delivering malicious AVS files to systems running vulnerable versions of ImageMagick, causing memory allocation to spiral out of control and consuming all available system resources.
Organizations affected by CVE-2017-7942 should immediately implement mitigations including updating to patched versions of ImageMagick, implementing input validation and file type restrictions, and deploying application-level firewalls or content filters to prevent processing of untrusted image files. System administrators should also consider implementing resource limits and monitoring for unusual memory consumption patterns, as outlined in the ATT&CK framework's resource exhaustion tactics. The vulnerability underscores the importance of proper memory management and input validation in image processing libraries, highlighting how seemingly benign file format parsing can become a critical security concern when proper safeguards are not implemented. Organizations should also consider implementing sandboxed environments for image processing operations and regularly auditing their image handling pipelines for similar memory management issues that could present analogous risks to their security posture.