CVE-2018-16640 in ImageMagick
Summary
by MITRE
ImageMagick 7.0.8-5 has a memory leak vulnerability in the function ReadOneJNGImage in coders/png.c.
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Analysis
by VulDB Data Team • 05/07/2023
The vulnerability identified as CVE-2018-16640 represents a critical memory leak flaw within ImageMagick's handling of JNG (JPEG Network Graphics) image files. This issue specifically affects version 7.0.8-5 of the ImageMagick library, which is widely used for image processing across numerous applications and systems. The memory leak occurs within the ReadOneJNGImage function located in the coders/png.c source file, indicating a fundamental weakness in how the library manages memory allocation during JNG file parsing operations. The vulnerability stems from improper memory management practices where allocated memory blocks are not properly released after processing JNG image data, leading to progressive memory consumption that can ultimately result in system instability or denial of service conditions.
The technical exploitation of this vulnerability involves crafting malicious JNG image files that trigger the memory leak during the image parsing process. When ImageMagick attempts to read such malformed JNG files, the ReadOneJNGImage function fails to properly deallocate memory resources that were allocated during the parsing of specific JNG metadata or image components. This memory leak behavior is particularly concerning because it can be triggered through various attack vectors including web applications that process user-uploaded images, email attachments, or file processing services that handle JNG format files. The flaw demonstrates poor resource management practices that align with CWE-401, which specifically addresses improper management of memory allocation and deallocation in software systems. The vulnerability's impact is amplified by the widespread adoption of ImageMagick across multiple platforms and applications, making it a prime target for attackers seeking to exploit memory management weaknesses.
From an operational perspective, this vulnerability creates significant risks for systems that rely on ImageMagick for image processing tasks, particularly in web applications, content management systems, and file processing services. The memory leak can cause progressive system degradation over time, leading to application crashes, system slowdowns, or complete system exhaustion of available memory resources. Attackers can leverage this vulnerability by uploading specifically crafted JNG files that cause the target system to consume increasing amounts of memory until the system becomes unresponsive or crashes entirely. The implications extend beyond simple denial of service as this memory leak could potentially be combined with other vulnerabilities to create more sophisticated attack vectors. According to ATT&CK framework, this vulnerability maps to T1499.004 which covers resource exhaustion attacks, and T1203 which addresses exploitation of software vulnerabilities for system compromise. The vulnerability affects systems running ImageMagick 7.0.8-5 and earlier versions, with the memory leak being particularly dangerous in environments where multiple image processing operations occur simultaneously, as the cumulative effect of memory leaks can rapidly exhaust system resources.
Mitigation strategies for CVE-2018-16640 should prioritize immediate patching of affected ImageMagick installations to version 7.0.8-6 or later, which contains the necessary memory management fixes. Organizations should implement input validation and sanitization measures to prevent processing of untrusted JNG files, particularly in web applications that accept user uploads. Network segmentation and access controls should be enforced to limit exposure to systems processing image files, while monitoring systems should be deployed to detect unusual memory consumption patterns that may indicate exploitation attempts. Additionally, system administrators should consider implementing memory limits and resource controls on image processing services to prevent complete system exhaustion. The fix addresses the root cause by ensuring proper memory deallocation in the ReadOneJNGImage function, thereby preventing the accumulation of unreleased memory blocks that previously led to the memory leak condition. Regular security audits and vulnerability assessments should be conducted to identify and remediate similar memory management issues in other image processing libraries and applications within the organization's infrastructure.