CVE-2017-14341 in ImageMagick
Summary
by MITRE
ImageMagick 7.0.6-6 has a large loop vulnerability in ReadWPGImage in coders/wpg.c, causing CPU exhaustion via a crafted wpg image file.
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Analysis
by VulDB Data Team • 12/28/2022
The vulnerability identified as CVE-2017-14341 represents a critical denial of service flaw within ImageMagick version 7.0.6-6, specifically affecting the ReadWPGImage function in the coders/wpg.c source file. This issue manifests as an excessive loop condition that consumes disproportionate CPU resources when processing maliciously crafted wpg image files. The vulnerability stems from inadequate input validation and loop boundary checking within the WPG (WordPerfect Graphics) image format parser, creating a scenario where a single malformed input file can trigger resource exhaustion attacks against systems processing such images. The flaw operates at the core level of image processing, making it particularly dangerous as it can affect any application or service that utilizes ImageMagick for image handling, including web applications, content management systems, and digital asset management platforms. This vulnerability directly maps to CWE-835, which describes the weakness of an infinite loop or a loop with an overly long iteration count, and represents a classic example of a resource exhaustion attack vector that can be exploited to disrupt service availability.
The technical exploitation of this vulnerability involves crafting a specific wpg image file that contains malformed loop parameters or recursive structures within its metadata or pixel data. When ImageMagick attempts to read this file through the ReadWPGImage function, the parsing logic enters into an infinite or extremely prolonged loop, causing the CPU utilization to spike dramatically. The loop continues until system resources are exhausted, potentially leading to system instability or complete service disruption. This particular implementation flaw demonstrates poor defensive programming practices where loop termination conditions are either missing or inadequately validated, allowing attackers to manipulate the parser behavior through carefully constructed input data. The vulnerability affects the broader ImageMagick ecosystem since the WPG format handler is part of the standard coders collection, meaning that any system utilizing ImageMagick for image processing is potentially vulnerable regardless of the specific application layer using the library.
From an operational impact perspective, this vulnerability poses significant risks to organizations relying on ImageMagick for image processing tasks, particularly in web environments where user-uploaded content is common. Attackers can leverage this flaw to perform denial of service attacks against web applications, file servers, or content management systems that process image uploads without proper input sanitization. The resource exhaustion effect can be particularly devastating in cloud environments or shared hosting scenarios where multiple processes compete for CPU resources, potentially causing cascading failures across multiple services. The vulnerability also aligns with ATT&CK technique T1499.004, which covers network denial of service attacks, and can be classified under T1595.001 for reconnaissance activities targeting system weaknesses. Organizations may experience service degradation, application crashes, or complete system outages, with recovery requiring either patch application or manual intervention to clear the resource consumption.
Mitigation strategies for CVE-2017-14341 primarily involve immediate patching of ImageMagick installations to versions that address the loop validation issue in the WPG image parser. System administrators should implement input validation measures at the application level, including file type checking, size limitations, and sandboxed processing environments for image files. Network-based mitigations can include implementing rate limiting on image upload endpoints and deploying intrusion detection systems to monitor for unusual CPU utilization patterns. Organizations should also consider implementing automated monitoring for resource exhaustion conditions and establish incident response procedures for handling such denial of service events. The vulnerability highlights the importance of regular security updates and comprehensive input validation practices, as well as the need for robust testing of third-party libraries against malicious inputs. Additionally, implementing proper access controls and limiting the scope of image processing capabilities within applications can reduce the attack surface and limit the potential impact of such vulnerabilities.