CVE-2017-7941 in ImageMagick
Summary
by MITRE
The ReadSGIImage function in sgi.c in ImageMagick 7.0.5-4 allows remote attackers to consume an amount of available memory via a crafted file.
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Analysis
by VulDB Data Team • 11/29/2022
The vulnerability identified as CVE-2017-7941 represents a critical memory consumption flaw within ImageMagick's handling of SGI image files. This issue affects version 7.0.5-4 of the widely used image processing library, which is employed across numerous applications and systems for image manipulation and conversion tasks. The vulnerability manifests in the ReadSGIImage function located within the sgi.c source file, where improper input validation and memory allocation handling creates an avenue for malicious actors to exploit memory exhaustion conditions.
The technical implementation of this vulnerability stems from insufficient bounds checking and memory allocation logic when processing specially crafted SGI image files. Attackers can construct malicious files that contain malformed data structures which, when processed by ImageMagick's ReadSGIImage function, trigger excessive memory allocation requests. This occurs because the function does not adequately validate the size parameters or data structure dimensions contained within the SGI file format, allowing crafted inputs to specify memory requirements that far exceed what is reasonable for legitimate image processing operations. The flaw operates as a denial-of-service vector where the targeted system's available memory is consumed until the process either crashes or becomes unresponsive.
The operational impact of CVE-2017-7941 extends beyond simple service disruption, as it can be leveraged in broader attack scenarios within web applications and file processing systems. When exploited, this vulnerability enables remote attackers to perform memory exhaustion attacks against systems running vulnerable versions of ImageMagick, potentially leading to system instability, resource starvation, and complete service unavailability. The vulnerability is particularly concerning in environments where ImageMagick is used as a backend processing component for user-uploaded content, as it allows attackers to target web applications through file upload mechanisms. This creates a significant risk for content management systems, image hosting services, and any application that processes user-provided image files without proper validation.
Mitigation strategies for CVE-2017-7941 should focus on immediate version updates to patched releases of ImageMagick, as well as implementing additional protective measures. Organizations should prioritize updating to ImageMagick versions that contain the appropriate fixes for this memory allocation vulnerability, typically found in versions released after the vulnerability disclosure. Network-based protections can include implementing file type validation and size limits for uploaded images, as well as deploying sandboxed processing environments for image files. The vulnerability aligns with CWE-129, which addresses improper validation of length parameters, and can be mapped to ATT&CK technique T1499.001 for resource exhaustion attacks. Additional defensive measures include configuring memory limits for image processing applications, implementing file content analysis to detect potentially malicious image structures, and establishing monitoring for unusual memory consumption patterns that may indicate exploitation attempts.