CVE-2018-14437 in ImageMagick
Summary
by MITRE
ImageMagick 7.0.8-4 has a memory leak in parse8BIM in coders/meta.c.
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Analysis
by VulDB Data Team • 04/25/2023
The vulnerability CVE-2018-14437 represents a critical memory management flaw within ImageMagick version 7.0.8-4 that specifically affects the parsing of 8BIM (8-Bit Image Management) metadata structures. This issue resides in the coders/meta.c file where the parse8BIM function fails to properly handle memory allocation and deallocation during the processing of certain image metadata. The flaw manifests when ImageMagick attempts to parse malformed or specially crafted 8BIM data blocks that are commonly found in Photoshop files and other image formats that support this metadata standard. The memory leak occurs because the application allocates memory for processing the metadata but does not subsequently free this memory, leading to progressive memory consumption over time.
The technical implementation of this vulnerability stems from inadequate memory management practices within the image processing pipeline. When ImageMagick encounters an 8BIM structure that contains unexpected or malformed data patterns, the parse8BIM function enters a code path where it allocates memory buffers to store intermediate parsing results. However, the function does not properly execute cleanup routines or memory deallocation code when certain error conditions are encountered or when processing concludes. This behavior creates a classic memory leak scenario where allocated memory remains in the process heap without being returned to the system, potentially leading to resource exhaustion. The vulnerability is particularly concerning because it can be triggered through the processing of image files that contain maliciously crafted 8BIM metadata, making it exploitable in scenarios where users or applications process untrusted image content.
The operational impact of CVE-2018-14437 extends beyond simple resource consumption to potentially enable denial of service attacks against systems running vulnerable ImageMagick versions. In server environments where ImageMagick is used for automated image processing, such as web applications, content management systems, or digital asset management platforms, this memory leak can cause gradual performance degradation and eventual system instability. Attackers could exploit this vulnerability by crafting specially formatted image files that trigger the memory leak during processing, potentially causing memory exhaustion on systems handling multiple concurrent image operations. The vulnerability aligns with CWE-401, which specifically addresses improper release of memory, and can be mapped to ATT&CK technique T1499.001 for resource exhaustion attacks. Systems that process large volumes of image files, particularly those that automatically convert or transform images, face the highest risk of exploitation as each processed file consumes additional memory without proper cleanup.
Mitigation strategies for CVE-2018-14437 should focus on immediate patching of vulnerable ImageMagick installations to version 7.0.8-10 or later, where the memory leak has been addressed through proper memory management implementation. Organizations should implement strict image validation and sanitization processes before processing any untrusted image content, including automated detection of malformed metadata structures. Network-based protections can include implementing rate limiting and resource monitoring to detect unusual memory consumption patterns that might indicate exploitation attempts. Additionally, system administrators should configure ImageMagick with reduced memory limits and implement process isolation for image processing tasks to contain potential impacts. The fix for this vulnerability demonstrates the importance of proper memory management in security-critical applications and highlights the need for comprehensive testing of metadata parsing functions to prevent similar issues in other software components. Regular security audits of image processing libraries and continuous monitoring for similar memory management flaws should be part of any comprehensive cybersecurity program to prevent exploitation of similar vulnerabilities in the future.