CVE-2016-2318 in GraphicsMagick
Summary
by MITRE
GraphicsMagick 1.3.23 allows remote attackers to cause a denial of service (NULL pointer dereference) via a crafted SVG file, related to the (1) DrawImage function in magick/render.c, (2) SVGStartElement function in coders/svg.c, and (3) TraceArcPath function in magick/render.c.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 08/10/2020
This vulnerability resides within GraphicsMagick version 1.3.23 and represents a critical denial of service flaw that can be exploited by remote attackers through carefully crafted svg files. The issue stems from improper input validation and handling within multiple functions that process svg graphics, creating a NULL pointer dereference condition that crashes the application. The vulnerability specifically affects three distinct functions within the GraphicsMagick codebase: DrawImage in magick/render.c, SVGStartElement in coders/svg.c, and TraceArcPath in magick/render.c, all of which are part of the graphics rendering pipeline that processes vector graphics.
The technical exploitation occurs when an attacker submits a malformed svg file that triggers the NULL pointer dereference in any of these three functions during the parsing and rendering process. The DrawImage function in render.c handles drawing operations and becomes vulnerable when processing malformed vector commands, while SVGStartElement in coders/svg.c fails to properly validate svg element structures before processing them. The TraceArcPath function in render.c specifically deals with arc path calculations and exhibits the same NULL pointer dereference behavior when encountering crafted arc parameters. These functions operate at different layers of the graphics processing stack, making the vulnerability particularly concerning as it can be triggered through multiple code paths.
The operational impact of this vulnerability extends beyond simple service disruption as it can be leveraged in various attack scenarios including web application exploitation, file upload attacks, and automated scanning systems. When exploited, the NULL pointer dereference causes the GraphicsMagick process to crash and terminate, effectively denying service to legitimate users who might be attempting to process valid graphics files. This vulnerability is particularly dangerous in web environments where GraphicsMagick is used as a backend image processing service, as attackers can systematically crash the service by submitting malicious svg files, potentially leading to complete service unavailability and resource exhaustion attacks.
Security professionals should consider this vulnerability in the context of CWE-476 which specifically addresses NULL pointer dereference conditions, and it aligns with ATT&CK technique T1499.004 for network denial of service attacks. The vulnerability demonstrates poor input validation practices and inadequate error handling within the graphics processing pipeline, which are common patterns in software security flaws. Organizations using GraphicsMagick in production environments should prioritize immediate patching to version 1.3.24 or later where these NULL pointer dereference issues have been resolved. Additionally, implementing proper input sanitization, file type validation, and resource limits on image processing services can provide additional defense-in-depth measures against similar vulnerabilities.
The broader implications of this vulnerability highlight the importance of robust input validation in multimedia processing libraries and the need for comprehensive testing of graphics rendering functions. Given that svg files are commonly used in web applications and email attachments, this vulnerability represents a significant risk to organizations that process user-uploaded graphics content. The fact that three different functions in the codebase can be exploited through similar attack vectors suggests a systemic issue in how the library handles malformed graphics data, indicating that similar vulnerabilities may exist in other parts of the codebase. This makes the vulnerability particularly concerning for security teams responsible for maintaining image processing services and web applications that rely on GraphicsMagick for their functionality.