CVE-2017-8765 in ImageMagick
Summary
by MITRE
The function named ReadICONImage in coders\icon.c in ImageMagick 7.0.5-5 has a memory leak vulnerability which can cause memory exhaustion via a crafted ICON file.
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Analysis
by VulDB Data Team • 12/06/2022
The vulnerability identified as CVE-2017-8765 resides within ImageMagick's ICON image format handling mechanism, specifically in the ReadICONImage function located in the coders\icon.c source file. This flaw represents a critical memory management issue that manifests when processing specially crafted ICON format files. The vulnerability affects ImageMagick version 7.0.5-5 and demonstrates how improper memory deallocation can lead to resource exhaustion attacks. The flaw operates by failing to properly release allocated memory blocks during the parsing process of malformed ICON files, creating a persistent memory leak condition that can be exploited by adversaries.
This memory leak vulnerability falls under the CWE-401 category of "Improper Release of Memory" and aligns with the ATT&CK technique T1499.003 for "Network Denial of Service" through resource exhaustion. The technical implementation involves the ReadICONImage function not correctly managing memory allocation patterns when encountering malformed ICON file structures. When an attacker provides a crafted ICON file with specific memory allocation patterns, the function allocates memory blocks but fails to properly de-allocate them upon completion of processing. This creates a progressive memory consumption issue that can eventually lead to system resource exhaustion.
The operational impact of this vulnerability extends beyond simple memory consumption, as it enables attackers to perform sustained resource exhaustion attacks against systems running vulnerable ImageMagick versions. The vulnerability is particularly dangerous in web applications and services that process user-uploaded images, as it allows attackers to consume system resources progressively until the target system becomes unresponsive or crashes entirely. This type of vulnerability can be leveraged in distributed denial of service scenarios where multiple instances of the memory leak can be triggered simultaneously across different systems.
Mitigation strategies for CVE-2017-8765 should prioritize immediate patching of affected ImageMagick installations to version 7.0.5-6 or later, which contains the necessary memory deallocation fixes. Organizations should implement input validation and sanitization measures for all image file processing pipelines, including MIME type verification and file format constraint enforcement. Network segmentation and rate limiting mechanisms can help reduce the impact of potential exploitation attempts. Additionally, implementing automated monitoring for unusual memory consumption patterns and establishing secure coding practices for image processing libraries can prevent similar vulnerabilities from emerging in future implementations. The fix implemented in the patched version addresses the root cause by ensuring proper memory deallocation during ICON file parsing operations, preventing the accumulation of unreleased memory blocks that characterize this class of denial of service vulnerabilities.