CVE-2018-17965 in ImageMagick
Summary
by MITRE
ImageMagick 7.0.7-28 has a memory leak vulnerability in WriteSGIImage in coders/sgi.c.
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Analysis
by VulDB Data Team • 05/22/2023
The vulnerability identified as CVE-2018-17965 represents a critical memory leak flaw within ImageMagick's SGI image format handling component. This issue specifically affects the WriteSGIImage function located in the coders/sgi.c source file, where improper memory management leads to unbounded memory consumption during image processing operations. The vulnerability manifests when ImageMagick attempts to write SGI image files, creating a condition where allocated memory blocks are not properly released back to the system. This memory leak occurs repeatedly with each affected image processing operation, gradually depleting available system resources and potentially leading to system instability or denial of service conditions.
From a technical perspective, the flaw stems from inadequate memory deallocation practices within the SGI image writing code path. The WriteSGIImage function fails to properly clean up dynamically allocated memory structures that are created during the encoding process for SGI format images. This type of vulnerability aligns with CWE-401, which categorizes improper memory management issues where allocated resources are not properly freed, creating persistent memory leaks that can accumulate over time. The vulnerability is particularly concerning because it affects a core image processing library that is widely deployed across various platforms and applications, making it a prime target for exploitation in resource exhaustion attacks.
The operational impact of this vulnerability extends beyond simple memory consumption issues, as it can significantly affect system performance and availability. When exploited, the memory leak can cause applications using ImageMagick to consume increasing amounts of RAM until system resources are exhausted, potentially leading to application crashes or complete system hangs. This makes the vulnerability particularly dangerous in server environments where ImageMagick is used for automated image processing tasks or in web applications that process user-uploaded images. The vulnerability can be exploited through various attack vectors including file upload functionality, automated image processing workflows, or when ImageMagick is integrated into larger applications that process SGI image formats.
Mitigation strategies for CVE-2018-17965 primarily involve immediate patching of affected ImageMagick installations to version 7.0.8-15 or later, which contains the necessary memory management fixes. Organizations should also implement proper input validation and sanitization measures to prevent malicious SGI image files from reaching the vulnerable code path. Additionally, system administrators should monitor memory usage patterns and implement resource limits on processes that utilize ImageMagick to prevent complete system exhaustion. The vulnerability demonstrates the importance of proper memory management practices in image processing libraries and aligns with ATT&CK technique T1499.001, which covers resource exhaustion attacks targeting memory availability. Organizations should also consider implementing sandboxing mechanisms and privilege separation to limit the potential impact of such vulnerabilities in their security architectures.