CVE-2017-12432 in ImageMagick
Summary
by MITRE
In ImageMagick 7.0.6-1, a memory exhaustion vulnerability was found in the function ReadPCXImage in coders/pcx.c, which allows attackers to cause a denial of service.
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Analysis
by VulDB Data Team • 12/14/2022
The vulnerability identified as CVE-2017-12432 represents a critical memory exhaustion issue within ImageMagick version 7.0.6-1, specifically affecting the ReadPCXImage function located in the coders/pcx.c source file. This flaw manifests as a denial of service condition that can be exploited by malicious actors to consume excessive system resources. The vulnerability stems from inadequate input validation and memory allocation handling when processing PCX image files, which are a legacy bitmap image format commonly used in older software environments. Attackers can craft specially malformed PCX files that trigger excessive memory allocation during the image parsing process, leading to system instability and potential service disruption.
From a technical perspective, the vulnerability operates through a classic memory exhaustion pattern where the ReadPCXImage function fails to properly validate the dimensions and structure of incoming PCX files before attempting to allocate memory resources. This function processes PCX image headers and pixel data without sufficient bounds checking, allowing attackers to specify arbitrarily large dimensions or malformed data structures that cause the application to allocate excessive memory blocks. The flaw aligns with CWE-122, which describes improper restriction of operations within the bounds of a memory buffer, and represents a clear example of how insufficient input validation can lead to resource exhaustion attacks. The vulnerability is particularly concerning because it can be triggered through simple file processing operations, making it accessible to attackers without requiring specialized privileges or complex exploitation techniques.
The operational impact of CVE-2017-12432 extends beyond simple denial of service conditions to potentially compromise entire systems that rely on ImageMagick for image processing tasks. When exploited, the vulnerability can cause applications using ImageMagick to consume all available memory resources, leading to system crashes, application hangs, or complete system instability. This is especially problematic in web applications, content management systems, or any environment where users can upload or process image files, as attackers can systematically exhaust system resources and render services unavailable to legitimate users. The vulnerability also aligns with ATT&CK technique T1499.004, which covers network denial of service attacks through resource exhaustion, making it a significant concern for organizations with web-facing applications that process user-uploaded content. The impact is further amplified in cloud environments where resource exhaustion can affect not only the targeted application but potentially other services running on the same infrastructure.
Mitigation strategies for CVE-2017-12432 must address both immediate protection and long-term system hardening. Organizations should immediately upgrade to ImageMagick version 7.0.6-2 or later, which contains the necessary patches to address the memory allocation issues in the ReadPCXImage function. Additionally, implementing proper input validation and resource limiting mechanisms can help prevent exploitation even if the underlying vulnerability persists. System administrators should consider implementing file size limits, image format restrictions, and memory monitoring for applications that process user-uploaded images. Network-level protections such as rate limiting and content filtering can also help reduce the impact of potential exploitation attempts. The vulnerability serves as a reminder of the importance of maintaining up-to-date software libraries and implementing robust input validation practices, as these measures form the foundation of effective security controls against resource exhaustion attacks. Organizations should also consider implementing automated patch management systems to ensure timely deployment of security updates and reduce the window of vulnerability exposure.