CVE-2017-14504 in GraphicsMagick
Summary
by MITRE
ReadPNMImage in coders/pnm.c in GraphicsMagick 1.3.26 does not ensure the correct number of colors for the XV 332 format, leading to a NULL Pointer Dereference.
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Analysis
by VulDB Data Team • 12/29/2022
The vulnerability identified as CVE-2017-14504 resides within GraphicsMagick version 1.3.26's ReadPNMImage function located in the coders/pnm.c file. This issue specifically affects the processing of XV 332 format image files, which represents a variant of the portable anymap format commonly used for storing raster graphics. The flaw manifests when the software fails to properly validate the number of colors associated with XV 332 format images, creating a condition where the application attempts to dereference a null pointer during image parsing operations. This particular format variant requires precise color channel handling and metadata validation to ensure proper rendering of image data.
The technical root cause of this vulnerability stems from inadequate input validation within the image parsing pipeline. When GraphicsMagick encounters an XV 332 formatted image file, the ReadPNMImage function does not perform proper bounds checking or color count verification before proceeding with memory operations. The XV 332 format specifically requires exactly 332 colors to be properly interpreted, but the implementation fails to enforce this constraint, allowing malformed input to bypass validation mechanisms. This deficiency creates a scenario where subsequent code attempts to access memory locations that have not been properly initialized, resulting in a NULL pointer dereference condition that can cause application crashes or unexpected termination.
The operational impact of this vulnerability extends beyond simple application instability, representing a potential denial of service vector that could be exploited by malicious actors. When an attacker crafts a specially formatted XV 332 image file with incorrect color specifications, they can trigger the null pointer dereference, causing the GraphicsMagick processing application to crash. This vulnerability affects any system that utilizes GraphicsMagick for image processing, including web applications, content management systems, and image handling services that may process user-uploaded images. The vulnerability aligns with CWE-476, which categorizes NULL pointer dereferences as a common programming error that can lead to application instability and potential security implications.
From a cybersecurity perspective, this vulnerability demonstrates the importance of proper input validation and memory safety practices in image processing libraries. The ATT&CK framework's technique T1203, "Exploitation for Execution," could potentially be leveraged through this vulnerability if an attacker can manipulate image processing workflows to trigger the null pointer dereference. Systems that automatically process or validate user-provided image content become particularly vulnerable, as they may inadvertently execute the flawed code path when handling maliciously crafted image files. The vulnerability also highlights the broader category of heap-based buffer overflows and memory corruption issues that plague image processing libraries, making it a critical concern for organizations relying on GraphicsMagick for image handling operations.
Mitigation strategies for this vulnerability should focus on immediate patching of GraphicsMagick installations to version 1.3.27 or later, which contains the necessary fixes for proper color validation. Organizations should implement input sanitization measures that validate image file formats before processing, including checking for proper color specifications in XV 332 format files. Network-level defenses such as content filtering and image validation proxies can provide additional protection layers, while application-level defenses should include proper error handling and exception management to prevent crash conditions from being exploited. Security monitoring should track for unusual image processing patterns that might indicate exploitation attempts, and regular security assessments should verify that all image processing components are properly updated and patched against known vulnerabilities.