CVE-2017-18251 in ImageMagick
Summary
by MITRE
An issue was discovered in ImageMagick 7.0.7. A memory leak vulnerability was found in the function ReadPCDImage in coders/pcd.c, which allow remote attackers to cause a denial of service via a crafted file.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 02/24/2023
The vulnerability identified as CVE-2017-18251 represents a critical memory leak flaw within ImageMagick version 7.0.7, specifically within the ReadPCDImage function located in the coders/pcd.c source file. This issue exposes systems to remote denial of service attacks through the careful crafting of malicious PCD image files that trigger excessive memory consumption during the image processing pipeline. The flaw demonstrates how image processing libraries can become attack vectors when proper input validation and memory management practices are not implemented effectively.
The technical implementation of this vulnerability stems from inadequate memory management within the PCD image reader component of ImageMagick's extensive library of image format handlers. When the ReadPCDImage function processes a specially crafted PCD file, it fails to properly release allocated memory resources, leading to progressive memory consumption that can eventually exhaust system resources. This memory leak pattern aligns with CWE-401, which categorizes improper handling of memory allocation and deallocation as a fundamental weakness in software security practices. The vulnerability operates at the intersection of input processing and resource management, where malformed input data triggers abnormal memory consumption patterns that can be exploited remotely.
From an operational perspective, this vulnerability poses significant risks to systems that process untrusted image files, particularly web applications, content management systems, and file upload services that utilize ImageMagick for image handling. Attackers can exploit this flaw by uploading or providing access to a maliciously crafted PCD file, which when processed by the vulnerable ImageMagick version will cause progressive memory exhaustion. The denial of service impact can manifest as application crashes, system slowdowns, or complete service unavailability, potentially affecting availability for legitimate users. This vulnerability particularly affects systems that automatically process images without proper sanitization or validation, creating a pathway for attackers to disrupt service availability through resource exhaustion attacks.
Mitigation strategies for CVE-2017-18251 should prioritize immediate patching of ImageMagick installations to versions that address this memory leak vulnerability, typically found in ImageMagick 7.0.8 and later releases. System administrators should implement proper input validation and sanitization measures for all image file uploads, including file type verification and size limitations to prevent exploitation. Network-level defenses such as implementing strict file type filters and content inspection mechanisms can provide additional protection layers. The vulnerability also highlights the importance of implementing proper resource limits and monitoring for memory usage patterns in applications that process external image files. Organizations should consider implementing sandboxing techniques and privilege separation when processing untrusted image content to limit the potential impact of such memory-related vulnerabilities. This case exemplifies the broader ATT&CK tactic of privilege escalation through resource exhaustion, where attackers leverage software weaknesses to consume system resources and cause service disruption.