CVE-2016-7515 in ImageMagick
Summary
by MITRE
The ReadRLEImage function in coders/rle.c in ImageMagick allows remote attackers to cause a denial of service (out-of-bounds read) via vectors related to the number of pixels.
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Analysis
by VulDB Data Team • 07/04/2024
The vulnerability identified as CVE-2016-7515 resides within the ImageMagick image processing library, specifically in the ReadRLEImage function located in the coders/rle.c file. This flaw represents a classic out-of-bounds read vulnerability that can be exploited by remote attackers to execute denial of service attacks against systems processing image files. The vulnerability manifests when the software processes Run-Length Encoded image data, a common format used for compressing raster graphics, particularly in scenarios where the number of pixels is not properly validated during parsing operations.
The technical implementation of this vulnerability stems from insufficient input validation within the ReadRLEImage function, which fails to properly check the boundaries of pixel count values during the decompression process. When an attacker crafts a malicious RLE image file with malformed pixel count parameters, the function attempts to read memory locations beyond the allocated buffer boundaries. This out-of-bounds memory access can result in unpredictable behavior including application crashes, system instability, or complete denial of service conditions. The vulnerability operates at the level of the image processing pipeline where raw image data is interpreted and converted into usable pixel information, making it particularly dangerous in web applications and image processing services that handle untrusted user uploads.
From an operational impact perspective, this vulnerability creates significant risks for organizations relying on ImageMagick for image handling operations. Systems that process user-generated content, image repositories, or provide image manipulation services become prime targets for exploitation. The remote nature of the attack means that malicious actors can trigger the vulnerability without requiring physical access to the target system, making it particularly dangerous in cloud environments and web applications. The denial of service aspect can lead to complete service disruption, affecting availability for legitimate users while potentially allowing attackers to conduct prolonged disruption campaigns. Organizations using ImageMagick in production environments face potential business impact ranging from temporary service interruptions to complete system unavailability during attack periods.
The vulnerability maps to CWE-125 Out-of-bounds Read within the Common Weakness Enumeration framework, which specifically addresses situations where software reads data past the end of a valid buffer. This weakness category encompasses various scenarios where boundary checks are insufficient or absent, leading to memory access violations. In the context of ATT&CK framework, this vulnerability aligns with the T1499.004 technique related to Network Denial of Service, where attackers leverage software flaws to consume system resources or cause service interruptions. The attack chain typically begins with an attacker preparing a malicious image file, followed by delivery through web forms, file upload mechanisms, or other attack vectors, ultimately leading to the execution of the out-of-bounds read condition.
Mitigation strategies for CVE-2016-7515 should prioritize immediate patching of ImageMagick installations to the latest versions that contain the necessary fixes for the ReadRLEImage function. Organizations should implement comprehensive input validation measures for all image processing operations, including the enforcement of strict file format checking and size limitations. Network-level defenses such as web application firewalls and content filtering systems can help detect and block suspicious image files before they reach the processing layer. Additionally, implementing proper memory protection mechanisms, including stack canaries and address space layout randomization, can help mitigate potential exploitation attempts. Regular security auditing of image processing pipelines and maintaining up-to-date security patches across all systems handling image data remains essential for preventing similar vulnerabilities from compromising system availability and integrity.