CVE-2016-4562 in ImageMagick
Summary
by MITRE
The DrawDashPolygon function in MagickCore/draw.c in ImageMagick before 6.9.4-0 and 7.x before 7.0.1-2 mishandles calculations of certain vertices integer data, which allows remote attackers to cause a denial of service (buffer overflow and application crash) or possibly have unspecified other impact via a crafted file.
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Analysis
by VulDB Data Team • 08/22/2022
The vulnerability identified as CVE-2016-4562 represents a critical buffer overflow condition within ImageMagick's graphics processing engine, specifically affecting the DrawDashPolygon function in MagickCore/draw.c. This flaw exists in versions prior to 6.9.4-0 and 7.x prior to 7.0.1-2, making it a widespread issue across multiple generations of the software. The vulnerability stems from improper handling of integer calculations when processing vertex data during polygon drawing operations, creating a scenario where maliciously crafted input can trigger unintended memory behavior.
The technical implementation of this vulnerability involves the DrawDashPolygon function failing to properly validate or constrain integer values representing polygon vertices, leading to arithmetic overflow conditions that ultimately result in buffer overflows. When ImageMagick processes graphics files containing specially crafted polygon data, the function performs calculations on vertex coordinates that exceed the allocated buffer boundaries. This integer overflow condition can occur during the computation of polygon dimensions or vertex positioning, where the calculated values surpass the maximum representable integer limits, causing memory corruption and subsequent application instability. The vulnerability operates at the intersection of integer arithmetic handling and memory management, creating a path for attackers to manipulate the graphics processing pipeline through carefully constructed input files.
From an operational perspective, this vulnerability presents significant risk to systems utilizing ImageMagick for image processing, particularly in web applications and content management systems where user-uploaded files are processed. Remote attackers can exploit this weakness by uploading malicious graphics files that trigger the vulnerable function during image parsing or rendering operations. The impact ranges from denial of service conditions causing application crashes and system instability to potentially more severe consequences including arbitrary code execution in certain environments. The vulnerability is particularly dangerous in server environments where ImageMagick is used to process untrusted input, as it can be leveraged to disrupt services or potentially gain unauthorized access to system resources. The attack surface expands significantly when considering that many web applications and services rely on ImageMagick for image manipulation, making this vulnerability a prime target for exploitation.
Mitigation strategies for CVE-2016-4562 primarily focus on immediate version upgrades to patched releases of ImageMagick, specifically versions 6.9.4-0 and 7.0.1-2 or later. System administrators should implement comprehensive patch management procedures to ensure all affected installations are updated promptly. Additional protective measures include implementing strict input validation for image files, employing sandboxing techniques to isolate image processing operations, and deploying network-based intrusion detection systems to monitor for exploitation attempts. The vulnerability aligns with CWE-190, which addresses integer overflow conditions, and can be mapped to ATT&CK technique T1203 for exploitation of software vulnerabilities. Organizations should also consider implementing file type restrictions and content filtering mechanisms to prevent processing of potentially malicious graphics files, while maintaining regular security assessments to identify and remediate similar vulnerabilities in other graphics processing libraries and components.