CVE-2017-16547 in GraphicsMagick
Summary
by MITRE
The DrawImage function in magick/render.c in GraphicsMagick 1.3.26 does not properly look for pop keywords that are associated with push keywords, which allows remote attackers to cause a denial of service (negative strncpy and application crash) or possibly have unspecified other impact via a crafted file.
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Analysis
by VulDB Data Team • 01/06/2023
The vulnerability identified as CVE-2017-16547 resides within the GraphicsMagick library version 1.3.26, specifically within the DrawImage function located in magick/render.c. This flaw represents a critical issue in the library's handling of image processing operations, particularly when dealing with push and pop keywords that are fundamental to GraphicsMagick's drawing command stack management system. The vulnerability stems from improper validation of keyword matching between push and pop operations, creating a scenario where maliciously crafted image files can trigger unexpected behavior in the application.
The technical implementation of this vulnerability involves a negative strncpy operation that occurs when the DrawImage function fails to properly verify that pop keywords correspond to their intended push keywords. This mismatch creates a condition where the application attempts to copy a negative number of bytes, leading to memory corruption and subsequent application crash. The flaw is classified under CWE-121 as a stack-based buffer overflow condition, though it manifests more specifically as a negative buffer copy operation that can result in arbitrary code execution or denial of service depending on the execution context. The vulnerability demonstrates characteristics consistent with CWE-787 which describes out-of-bounds write conditions, though in this case the manifestation is through negative string operations rather than direct buffer overflows.
Operational impact of this vulnerability extends beyond simple denial of service scenarios, as remote attackers can potentially leverage this weakness to execute arbitrary code on systems running vulnerable versions of GraphicsMagick. The vulnerability affects any application that utilizes GraphicsMagick's image processing capabilities, including web applications, content management systems, and image processing services that accept user-uploaded files. The remote attack vector means that exploitation can occur without requiring local system access, making it particularly dangerous in web environments where users might upload or browse images. Attackers can craft specially formatted image files that, when processed by GraphicsMagick, will trigger the negative strncpy operation and cause the application to crash or potentially execute unintended code, depending on the memory layout and system configuration.
Mitigation strategies for CVE-2017-16547 should prioritize immediate patching of GraphicsMagick installations to version 1.3.27 or later, where the vulnerability has been addressed through proper validation of push-pop keyword matching. Organizations should implement input validation measures that restrict image file uploads to trusted sources and employ file format verification before processing. Network segmentation and application sandboxing can help contain potential exploitation attempts, while monitoring systems should be configured to detect unusual application crashes or memory access patterns. The ATT&CK framework categorizes this vulnerability under T1203 as Exploitation for Client Execution, with potential for T1059 for Command and Scripting Interpreter if exploitation leads to code execution. Additionally, organizations should consider implementing automated vulnerability scanning tools that can detect the presence of vulnerable GraphicsMagick versions in their infrastructure and ensure that all image processing components are regularly updated and patched according to vendor security advisories.