CVE-2018-16328 in ImageMagick
Summary
by MITRE
In ImageMagick before 7.0.8-8, a NULL pointer dereference exists in the CheckEventLogging function in MagickCore/log.c.
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Analysis
by VulDB Data Team • 05/06/2023
The vulnerability identified as CVE-2018-16328 represents a critical NULL pointer dereference flaw within ImageMagick's logging subsystem, specifically affecting versions prior to 7.0.8-8. This issue resides in the CheckEventLogging function located within the MagickCore/log.c source file, making it a fundamental component of the software's event handling and logging infrastructure. The vulnerability demonstrates a classic memory safety issue that can potentially lead to application crashes or more severe exploitation scenarios when processing malformed input files.
The technical flaw manifests when the CheckEventLogging function attempts to dereference a pointer that has not been properly initialized or validated, resulting in a NULL pointer dereference condition. This occurs during the event logging process when ImageMagick processes certain image files that trigger the logging mechanism to execute. The function fails to perform adequate null checks before accessing memory locations, creating an exploitable condition that can be leveraged by malicious actors. This type of vulnerability falls under CWE-476 which specifically addresses NULL pointer dereference conditions in software implementations.
The operational impact of this vulnerability extends beyond simple application instability, as it can be exploited to cause denial of service conditions or potentially enable more sophisticated attack vectors. When an attacker crafts a malicious image file that triggers the vulnerable code path, the application crashes due to the NULL pointer dereference, effectively causing a denial of service for legitimate users. In certain environments where ImageMagick is used in automated processing pipelines or web applications, this vulnerability could be weaponized to disrupt services continuously. The vulnerability is particularly concerning in environments where ImageMagick processes untrusted user input, as it provides a straightforward method for attackers to cause system instability.
Mitigation strategies for CVE-2018-16328 primarily involve upgrading to ImageMagick version 7.0.8-8 or later, which contains the necessary patches to address the NULL pointer dereference issue. System administrators should prioritize this update across all environments where ImageMagick is deployed, particularly in web applications and automated processing systems. Additional defensive measures include implementing proper input validation and sanitization when processing image files, employing sandboxing techniques to isolate ImageMagick operations, and monitoring for unusual application behavior that might indicate exploitation attempts. Organizations should also consider implementing network segmentation and access controls to limit the potential impact of successful exploitation attempts, as this vulnerability aligns with attack patterns documented in the MITRE ATT&CK framework under the T1499 category for network denial of service attacks. The vulnerability demonstrates the importance of proper memory management and input validation in security-critical software components, emphasizing the need for comprehensive testing and code review processes to identify similar issues in other software libraries.