CVE-2017-6501 in ImageMagick
Summary
by MITRE
An issue was discovered in ImageMagick 6.9.7. A specially crafted xcf file could lead to a NULL pointer dereference.
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Analysis
by VulDB Data Team • 09/04/2020
The vulnerability identified as CVE-2017-6501 represents a critical null pointer dereference flaw within ImageMagick version 6.9.7, specifically when processing specially crafted xcf files. This issue stems from inadequate input validation and error handling mechanisms within the image processing library, which is widely used for handling various image formats across numerous applications and systems. The xcf file format is native to the GIMP image editor, and when ImageMagick attempts to parse such files without proper safeguards, it can encounter unexpected null references that lead to application crashes or potential exploitation scenarios.
The technical root cause of this vulnerability lies in the improper handling of memory references during the parsing process of xcf files. When ImageMagick encounters malformed or maliciously constructed xcf data structures, the software fails to adequately validate pointer references before dereferencing them, resulting in a null pointer dereference condition. This class of vulnerability is categorized under CWE-476 as NULL Pointer Dereference, which represents a fundamental memory safety issue where code attempts to access memory through a null pointer reference. The flaw manifests when the image processing pipeline encounters unexpected data patterns that cause internal pointers to remain uninitialized or set to null values, leading to immediate program termination or potential code execution control flow manipulation.
From an operational perspective, this vulnerability poses significant risks to systems that utilize ImageMagick for image processing tasks, particularly in web applications, content management systems, and automated image handling workflows. Attackers could exploit this weakness by uploading malicious xcf files to systems that process user-uploaded content, potentially causing denial of service through application crashes or more severe consequences if the null pointer dereference can be manipulated to achieve arbitrary code execution. The impact extends beyond simple service disruption as the vulnerability could be leveraged in broader attack chains, especially when ImageMagick is integrated into larger software ecosystems where such failures might cascade into more complex system compromises.
Organizations utilizing ImageMagick should prioritize immediate remediation through official patches provided by the ImageMagick development team, as the vulnerability affects the core image processing functionality that underpins numerous security-critical applications. Mitigation strategies should include implementing robust input validation for all image file types, particularly those from untrusted sources, and deploying network-level restrictions that limit access to image processing endpoints. The vulnerability aligns with ATT&CK technique T1203 as it represents a method for achieving system compromise through software exploitation, and organizations should consider implementing sandboxing mechanisms for image processing operations to contain potential impacts. Additionally, regular security assessments of image processing pipelines and comprehensive monitoring for anomalous application behavior can help detect exploitation attempts before they cause significant damage.