CVE-2018-16413 in ImageMagick
Summary
by MITRE
ImageMagick 7.0.8-11 Q16 has a heap-based buffer over-read in the MagickCore/quantum-private.h PushShortPixel function when called from the coders/psd.c ParseImageResourceBlocks function.
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Analysis
by VulDB Data Team • 05/06/2023
The vulnerability CVE-2018-16413 represents a critical heap-based buffer over-read flaw within ImageMagick version 7.0.8-11 Q16 that exposes systems to potential exploitation through malicious image files. This issue occurs in the MagickCore/quantum-private.h file within the PushShortPixel function, which is invoked by the coders/psd.c ParseImageResourceBlocks function during processing of Photoshop Document format files. The flaw demonstrates a classic memory safety issue where the application reads beyond the allocated memory boundaries when handling specific image resource blocks in psd files. The vulnerability is particularly concerning because it can be triggered through image processing operations that are commonly encountered in web applications, file upload systems, and document handling services. Attackers can craft specially formatted psd files that, when processed by ImageMagick, cause the application to read memory locations beyond the intended buffer boundaries, potentially leading to information disclosure, application crashes, or in some cases, arbitrary code execution depending on the memory layout and exploitation conditions.
The technical nature of this vulnerability aligns with CWE-125, which describes "Out-of-bounds Read" conditions where a program reads data past the end of a buffer or other data structure. The flaw specifically manifests when the PushShortPixel function attempts to read short pixel values from memory locations that have not been properly validated against buffer boundaries. This occurs during the parsing of image resource blocks in psd files, where the application fails to properly validate the size and structure of resource data before attempting to process it. The issue is particularly dangerous because it can be exploited through file upload vulnerabilities, where an attacker uploads a malicious psd file that triggers the vulnerable code path during image processing. The heap-based nature of the over-read means that the memory corruption occurs in dynamically allocated heap memory, making the exploitation more complex but potentially more reliable than stack-based overflows. This vulnerability demonstrates a lack of proper input validation and bounds checking in the image processing pipeline, particularly when handling structured data formats like psd files.
The operational impact of CVE-2018-16413 extends beyond simple application instability to potentially enable more sophisticated attacks in environments where ImageMagick is used for automated image processing. Systems that process user-uploaded images, render web content, or handle document conversions become vulnerable to denial-of-service attacks that can crash services or cause memory corruption. The vulnerability affects any application or service that uses ImageMagick 7.0.8-11 Q16 for psd file processing, including web applications, content management systems, and automated document handling platforms. In environments where ImageMagick is used as part of a broader security infrastructure, such as malware analysis systems or digital forensics tools, this vulnerability could potentially be leveraged to extract sensitive information from memory or disrupt critical operations. The exploitation of this vulnerability can be automated through file upload mechanisms, making it particularly dangerous in web applications that do not properly validate or sanitize image file inputs before processing.
Mitigation strategies for CVE-2018-16413 should focus on immediate patching of affected ImageMagick installations to version 7.0.8-12 or later, which contains the necessary fixes for the buffer over-read issue. Organizations should implement strict input validation and sanitization measures for all image file processing operations, particularly for psd and other complex image formats that may contain structured resource data. Network-based mitigations should include implementing file type restrictions and content scanning for image uploads to prevent malicious files from reaching the ImageMagick processing pipeline. Security teams should also consider implementing application-level sandboxes or containerization for image processing operations to limit the potential impact of successful exploits. Additionally, monitoring and logging of image processing activities can help detect potential exploitation attempts, while regular security assessments should verify that all ImageMagick installations are properly updated and that no older vulnerable versions remain in production environments. The vulnerability also highlights the importance of proper memory safety practices in image processing libraries and the need for comprehensive input validation across all data processing functions.