CVE-2017-14138 in ImageMagick
Summary
by MITRE
ImageMagick 7.0.6-5 has a memory leak vulnerability in ReadWEBPImage in coders/webp.c because memory is not freed in certain error cases, as demonstrated by VP8 errors.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 12/27/2022
The vulnerability identified as CVE-2017-14138 represents a critical memory leak flaw within ImageMagick's WebP image processing functionality. This issue specifically affects ImageMagick version 7.0.6-5 and stems from improper memory management during error handling scenarios. The vulnerability manifests in the ReadWEBPImage function located within the coders/webp.c source file, where allocated memory resources are not properly released when encountering certain VP8 decoding errors. This memory leak vulnerability constitutes a significant security risk as it can be exploited through crafted WebP image files that trigger the error conditions, leading to progressive memory consumption that can eventually exhaust system resources.
The technical implementation of this vulnerability demonstrates a classic memory management flaw that aligns with CWE-401, which specifically addresses "Improper Release of Memory Before Removing Last Reference" in software systems. When ImageMagick processes WebP images containing VP8 errors, the code path fails to execute proper cleanup routines that would normally free previously allocated memory blocks. This failure occurs during error handling conditions where the application attempts to gracefully manage decoding failures but neglects to properly dispose of allocated memory resources. The vulnerability is particularly concerning because it operates within the image processing pipeline where malicious actors can leverage it through crafted input files, making it a potential vector for denial of service attacks or resource exhaustion scenarios.
From an operational impact perspective, this memory leak vulnerability creates substantial risks for systems that process untrusted image content, particularly those running ImageMagick as part of web applications, content management systems, or file processing services. The progressive nature of memory consumption means that repeated exploitation can lead to system instability, application crashes, or complete system resource exhaustion. Attackers can craft malicious WebP files that, when processed by vulnerable ImageMagick installations, will trigger the memory leak conditions repeatedly, potentially causing denial of service against legitimate users. The vulnerability's impact extends beyond simple resource consumption as it can also affect system performance and availability, particularly in environments where ImageMagick is used extensively for image processing tasks.
Mitigation strategies for CVE-2017-14138 should prioritize immediate patching of affected ImageMagick installations to version 7.0.6-6 or later, which contains the necessary memory cleanup fixes. Organizations should implement input validation and sanitization measures to restrict image file processing, particularly when handling untrusted content from external sources. Network-level defenses can include implementing file type validation and limiting image processing capabilities to known good file formats. System administrators should monitor for unusual memory consumption patterns and implement resource limits on image processing services to prevent complete system exhaustion. Additionally, organizations should consider implementing sandboxing techniques for image processing operations and regularly audit their image handling code paths to identify similar memory management issues that might exist in other components. This vulnerability exemplifies the importance of proper error handling and memory management practices in security-critical software components, aligning with ATT&CK technique T1499.004 for resource exhaustion attacks through memory leaks.