CVE-2019-17541 in ImageMagick
Summary
by MITRE
ImageMagick before 7.0.8-55 has a use-after-free in DestroyStringInfo in MagickCore/string.c because the error manager is mishandled in coders/jpeg.c.
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Analysis
by VulDB Data Team • 01/08/2024
The vulnerability identified as CVE-2019-17541 represents a critical use-after-free condition within ImageMagick's string handling mechanisms, specifically affecting versions prior to 7.0.8-55. This flaw exists in the DestroyStringInfo function located in MagickCore/string.c and stems from improper error management within the jpeg.c coder module. The issue manifests when ImageMagick processes malformed jpeg image files, creating a scenario where freed memory regions are accessed after the original allocation has been released. This fundamental memory management error creates a dangerous state where attackers can potentially execute arbitrary code or cause application crashes through carefully crafted malicious input files.
The technical root cause of this vulnerability aligns with CWE-416, which defines use-after-free conditions as a common class of memory safety issues. The flaw occurs during the destruction phase of string information objects when the error handling mechanism in the jpeg coder fails to properly manage the lifecycle of allocated memory resources. When processing jpeg files, the jpeg.c module does not correctly handle error states that should prevent access to freed memory structures, allowing for the possibility of dangling pointer dereferences. This improper error management creates an exploitable condition where the application's memory state becomes corrupted, potentially enabling attackers to manipulate program execution flow.
From an operational perspective, this vulnerability presents significant risks to systems that process untrusted image files, particularly those running ImageMagick versions below the patched threshold. The attack surface is extensive given ImageMagick's widespread adoption in web applications, content management systems, and image processing pipelines. An attacker could craft malicious jpeg files that, when processed by vulnerable ImageMagick implementations, would trigger the use-after-free condition. This could lead to denial of service attacks through application crashes or more severe exploitation scenarios where remote code execution becomes possible. The vulnerability's impact is amplified in environments where ImageMagick is used to process user-uploaded content without proper sanitization, making it a prime target for exploitation in web-based attack vectors.
The mitigation strategy for CVE-2019-17541 requires immediate patching of ImageMagick installations to version 7.0.8-55 or later, which contains the necessary fixes to properly handle error conditions in the jpeg coder module. Organizations should also implement comprehensive input validation and sanitization measures for all image processing workflows, particularly those involving untrusted user uploads. Network segmentation and access controls should be enforced to limit exposure of vulnerable systems, while regular security assessments should verify that all ImageMagick installations are properly updated. Additionally, implementing application-level sandboxing and privilege separation can help contain potential exploitation attempts, reducing the overall impact should the vulnerability be successfully exploited. This vulnerability demonstrates the critical importance of proper error handling in memory management and aligns with ATT&CK technique T1059 for executing malicious code through compromised image processing applications.