CVE-2017-14733 in GraphicsMagick
Summary
by MITRE
ReadRLEImage in coders/rle.c in GraphicsMagick 1.3.26 mishandles RLE headers that specify too few colors, which allows remote attackers to cause a denial of service (heap-based buffer over-read and application crash) via a crafted file.
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Analysis
by VulDB Data Team • 12/30/2022
The vulnerability identified as CVE-2017-14733 represents a critical heap-based buffer over-read flaw within GraphicsMagick version 1.3.26, specifically within the ReadRLEImage function located in the coders/rle.c file. This issue stems from inadequate validation of RLE (Run-Length Encoding) headers during image processing operations, creating a pathway for remote attackers to exploit the software through carefully crafted malicious files. The flaw manifests when the RLE header specifies a color count that is insufficient for the actual image data, leading to memory access violations that result in application instability and potential system crashes.
The technical implementation of this vulnerability involves the improper handling of RLE image format specifications where the software fails to validate the consistency between the declared color palette size in the header and the actual data structure. When GraphicsMagick processes an image file with malformed RLE headers, the application attempts to read beyond the allocated memory boundaries, triggering a buffer over-read condition that can be leveraged to execute arbitrary code or cause complete application termination. This type of vulnerability falls under the CWE-125 weakness category, which specifically addresses out-of-bounds read conditions that can lead to information disclosure, system crashes, and potential privilege escalation scenarios.
From an operational perspective, this vulnerability presents significant risks to systems that process untrusted image files, particularly those utilizing GraphicsMagick for image conversion, manipulation, or web-based image handling services. Attackers can exploit this flaw by uploading or transmitting specially crafted RLE image files that trigger the memory corruption during parsing operations. The impact extends beyond simple denial of service, as the heap-based nature of the vulnerability can potentially be leveraged to achieve more sophisticated attacks such as code execution or privilege escalation depending on the target system configuration and memory layout. The vulnerability demonstrates characteristics consistent with ATT&CK technique T1203, which involves the exploitation of software flaws to gain unauthorized access or cause system instability.
The mitigation strategies for CVE-2017-14733 primarily involve upgrading to GraphicsMagick version 1.3.27 or later, where the issue has been resolved through improved input validation and memory boundary checks. Additionally, implementing proper input sanitization measures, deploying network segmentation, and utilizing sandboxing techniques can help reduce the attack surface and limit potential exploitation. Organizations should also consider implementing automated monitoring for suspicious file processing activities and establishing robust patch management procedures to ensure timely remediation of similar vulnerabilities. The fix implemented in the updated version addresses the core issue by enforcing strict validation of RLE header parameters and implementing proper bounds checking mechanisms to prevent unauthorized memory access patterns.