CVE-2017-14137 in ImageMagick
Summary
by MITRE
ReadWEBPImage in coders/webp.c in ImageMagick 7.0.6-5 has a issue where memory allocation is excessive because it depends only on a length field in a header.
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Analysis
by VulDB Data Team • 12/27/2022
The vulnerability identified as CVE-2017-14137 represents a critical memory allocation flaw within ImageMagick's WebP image processing functionality. This issue exists in the ReadWEBPImage function located in the coders/webp.c file of ImageMagick version 7.0.6-5, where the software fails to properly validate memory allocation requests based solely on the length field present in the WebP file header. The flaw stems from insufficient input validation mechanisms that allow maliciously crafted WebP files to trigger excessive memory consumption during image processing operations. This vulnerability falls under the category of memory corruption issues and specifically aligns with CWE-129, which addresses insufficient validation of length fields, and CWE-704, covering incorrect type casting that can lead to memory allocation problems.
The technical exploitation of this vulnerability occurs when ImageMagick processes a malformed WebP image file that contains an inflated length field in its header structure. The software's parsing logic relies exclusively on this header value to determine the amount of memory to allocate for image data processing, without implementing proper bounds checking or validation against expected image dimensions and data structures. This primitive approach to memory management creates a scenario where an attacker can craft a WebP file with a header containing a deceptive length value that is significantly larger than the actual file size or the reasonable memory requirements for valid WebP data. When the ReadWEBPImage function attempts to allocate memory based on this manipulated header value, it consumes excessive system resources, potentially leading to memory exhaustion and application instability.
The operational impact of this vulnerability extends beyond simple resource consumption, as it creates potential denial of service conditions that can affect systems processing WebP images. When exploited in environments where ImageMagick is used for image handling, such as web applications, content management systems, or digital asset management platforms, this flaw can enable attackers to consume excessive memory resources and potentially cause system crashes or application hangs. The vulnerability is particularly concerning in server environments where multiple image processing operations occur concurrently, as the memory exhaustion can cascade and affect overall system performance. Additionally, this issue can be leveraged as part of broader attack chains, potentially enabling more sophisticated exploitation techniques that combine memory corruption vulnerabilities with other attack vectors.
Organizations should implement immediate mitigations including updating to patched versions of ImageMagick where the memory allocation validation has been strengthened to include proper bounds checking and header validation. The recommended approach involves deploying security patches that enforce strict validation of header fields against expected data ranges and implement proper memory allocation limits that prevent excessive consumption. System administrators should also consider implementing input validation controls at network boundaries and file processing layers to prevent malicious WebP files from reaching the ImageMagick processing components. From an ATT&CK perspective, this vulnerability aligns with the T1499.004 technique related to network denial of service and the T1059.007 technique involving command and scripting interpreter usage for exploitation. Organizations should also consider implementing runtime monitoring to detect unusual memory allocation patterns and implement proper access controls to limit the scope of potential exploitation.