CVE-2016-7996 in GraphicsMagick
Summary
by MITRE
Heap-based buffer overflow in the WPG format reader in GraphicsMagick 1.3.25 and earlier allows remote attackers to have unspecified impact via a colormap with a large number of entries.
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Analysis
by VulDB Data Team • 05/13/2026
The heap-based buffer overflow vulnerability in GraphicsMagick's WPG format reader represents a critical security flaw that affects versions 1.3.25 and earlier. This vulnerability resides within the handling of WPG (Word Perfect Graphics) image files, which are commonly used for vector graphics and bitmap images in various document processing applications. The flaw manifests when the software processes a WPG file containing a colormap with an excessive number of color entries, creating a condition where memory allocation does not properly account for the actual data size. This type of vulnerability falls under the CWE-122 category for heap-based buffer overflow, where insufficient bounds checking allows attackers to write beyond allocated memory boundaries.
The technical implementation of this vulnerability occurs during the parsing of WPG format files where GraphicsMagick attempts to read and process colormap data. When an attacker crafts a malicious WPG file with an inflated colormap entry count, the software's memory allocation routines fail to properly validate the actual number of entries against the allocated buffer space. This mismatch allows for memory corruption that can be exploited to overwrite adjacent heap memory regions. The vulnerability's remote exploitability means that attackers can deliver malicious WPG files through web applications, email attachments, or file sharing systems without requiring local access to the target system. The unspecified impact mentioned in the CVE description indicates that successful exploitation could lead to arbitrary code execution, denial of service, or information disclosure depending on the specific memory layout and exploitation techniques employed.
From an operational perspective, this vulnerability presents significant risks to organizations relying on GraphicsMagick for image processing, particularly in web applications that accept user-uploaded images. The impact extends beyond simple application crashes to potentially allow full system compromise when exploited successfully. Attackers could leverage this vulnerability to execute malicious code with the privileges of the GraphicsMagick process, which typically runs with elevated permissions when processing image files. The vulnerability affects a wide range of applications that depend on GraphicsMagick for image conversion and manipulation, including web servers, content management systems, and document processing platforms. This type of vulnerability aligns with ATT&CK technique T1203 for Exploitation for Client Execution, where attackers exploit software vulnerabilities to gain unauthorized access to systems through legitimate application interfaces.
The recommended mitigation strategy involves immediate upgrading to GraphicsMagick version 1.3.26 or later, which contains the necessary patches to address the buffer overflow condition. Organizations should also implement strict input validation measures that limit the size and complexity of image files processed by applications using GraphicsMagick. Network segmentation and application whitelisting can provide additional defense-in-depth measures to limit potential attack vectors. Security monitoring should be enhanced to detect unusual image processing activities that might indicate exploitation attempts. The vulnerability demonstrates the importance of proper bounds checking in memory management operations and highlights the need for comprehensive security testing of image processing libraries. Regular security updates and vulnerability assessments should be implemented as part of the software development lifecycle to prevent similar issues from arising in the future. Organizations should also consider implementing sandboxing techniques for image processing operations to limit the potential impact of successful exploitation attempts.