CVE-2016-8682 in GraphicsMagick
Summary
by MITRE
The ReadSCTImage function in coders/sct.c in GraphicsMagick 1.3.25 allows remote attackers to cause a denial of service (out-of-bounds read) via a crafted SCT header.
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Analysis
by VulDB Data Team • 08/15/2020
The vulnerability identified as CVE-2016-8682 resides within the GraphicsMagick library's image processing capabilities, specifically in the ReadSCTImage function located in coders/sct.c. This flaw represents a classic out-of-bounds read vulnerability that can be exploited by remote attackers to trigger a denial of service condition. GraphicsMagick, a robust image processing library, is widely utilized in web applications, content management systems, and various software platforms that handle image file processing, making this vulnerability particularly concerning from a security perspective. The SCT file format, which stands for Synchronized Multimedia Integration Language or similar structured data formats, is processed by GraphicsMagick to handle specific image data types, but the implementation contains a critical flaw in how it parses the header information.
The technical nature of this vulnerability stems from insufficient input validation and boundary checking within the ReadSCTImage function. When processing a crafted SCT header, the function fails to properly validate the size or structure of the header data before attempting to read from memory locations that may extend beyond the allocated buffer boundaries. This type of vulnerability falls under the Common Weakness Enumeration category CWE-125, which specifically addresses out-of-bounds read conditions. The flaw occurs during the parsing phase where the software assumes certain data structures will conform to expected formats without adequate verification, leading to memory access violations that can crash the application or cause unexpected behavior. Attackers can craft malicious SCT files with malformed headers that, when processed by GraphicsMagick, trigger the out-of-bounds memory access.
The operational impact of this vulnerability extends beyond simple service disruption to potentially enable more sophisticated attack vectors. Remote attackers who can influence the processing of SCT images can cause denial of service conditions that may affect web applications, image processing services, or any system that relies on GraphicsMagick for image handling. This can result in application crashes, system instability, or complete service unavailability, particularly in environments where image processing is a core functionality. The vulnerability is especially dangerous in web-facing applications where users might upload images, as attackers could exploit this to bring down services or create resource exhaustion conditions that could be leveraged as part of broader attack campaigns. From an attacker's perspective, this vulnerability aligns with ATT&CK technique T1499.004, which involves network denial of service attacks, and can be used to establish persistent service disruption against target systems.
Mitigation strategies for CVE-2016-8682 should focus on immediate patching of GraphicsMagick installations to version 1.3.26 or later, which contains the necessary fixes for the out-of-bounds read condition. Organizations should implement proper input validation and sanitization measures for all image file processing pipelines, including the implementation of strict file format validation and size checking before any processing occurs. Network-level protections such as web application firewalls and content filtering systems can help detect and block malicious SCT files before they reach the image processing components. Additionally, implementing proper error handling and graceful degradation mechanisms can help prevent complete service failures when encountering malformed input. Security monitoring should include detection of unusual processing patterns or memory access violations that might indicate exploitation attempts, while regular security audits of image processing workflows should be conducted to identify other potential vulnerabilities in the system architecture.