CVE-2019-19950 in GraphicsMagick
Summary
by MITRE
In GraphicsMagick 1.4 snapshot-20190403 Q8, there is a use-after-free in ThrowException and ThrowLoggedException of magick/error.c.
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Analysis
by VulDB Data Team • 03/16/2024
The vulnerability identified as CVE-2019-19950 represents a critical use-after-free condition affecting GraphicsMagick version 1.4 snapshot-20190403 Q8. This flaw manifests within the error handling mechanisms of the graphics processing library, specifically in the ThrowException and ThrowLoggedException functions located in the magick/error.c source file. The issue arises when the application processes malformed or malicious image files that trigger error conditions, leading to improper memory management during exception handling. Such vulnerabilities are particularly dangerous in image processing libraries that are widely used across various applications and systems for handling multimedia content.
The technical implementation of this vulnerability stems from improper memory deallocation practices within the error reporting subsystem. When an error condition is encountered and the ThrowException or ThrowLoggedException functions are invoked, the code path fails to properly manage memory references before freeing allocated resources. This creates a scenario where memory locations that were previously freed become accessible for reuse, potentially allowing attackers to manipulate the freed memory through subsequent operations. The flaw is classified under CWE-416 as Use After Free, which represents a well-documented vulnerability pattern where software attempts to access memory after it has been freed, leading to unpredictable behavior and potential exploitation.
The operational impact of this vulnerability extends beyond simple application crashes, as it can potentially enable remote code execution in scenarios where GraphicsMagick is used to process untrusted image content. Attackers could craft malicious image files that, when processed by vulnerable applications, trigger the use-after-free condition and subsequently exploit it to execute arbitrary code with the privileges of the affected process. This risk is particularly significant in web applications, content management systems, and any environment where users can upload or process image files from untrusted sources. The vulnerability affects the core error handling functionality of GraphicsMagick, making it a critical issue for any system relying on this library for image processing tasks.
Mitigation strategies for CVE-2019-19950 should prioritize immediate patching of affected GraphicsMagick installations to the latest stable releases that contain memory management fixes for the error handling subsystem. Organizations should implement strict input validation and sanitization for all image file processing workflows, particularly when handling user-uploaded content. Network segmentation and application whitelisting can help reduce the attack surface by limiting direct access to vulnerable applications. Additionally, monitoring systems should be configured to detect unusual memory access patterns or error handling behavior that might indicate exploitation attempts. The vulnerability aligns with ATT&CK technique T1203 - Exploitation for Client Execution, as it enables attackers to execute code through manipulation of memory structures during error conditions. Regular security assessments and dependency updates remain essential practices to prevent similar vulnerabilities from being exploited in production environments.