CVE-2016-7997 in GraphicsMagick
Summary
by MITRE
The WPG format reader in GraphicsMagick 1.3.25 and earlier allows remote attackers to cause a denial of service (assertion failure and crash) via vectors related to a ReferenceBlob and a NULL pointer.
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Analysis
by VulDB Data Team • 05/13/2026
The vulnerability identified as CVE-2016-7997 resides within the GraphicsMagick library's WPG format reader implementation, affecting versions 1.3.25 and earlier. This flaw represents a critical security issue that enables remote attackers to execute denial of service attacks against systems processing WPG image files. The vulnerability specifically manifests when the WPG reader encounters malformed or specially crafted ReferenceBlob structures that lead to assertion failures and subsequent application crashes. The underlying technical mechanism involves improper handling of NULL pointers during the parsing of WPG format metadata, where the code fails to validate pointer references before dereferencing them. This type of vulnerability falls under the category of improper input validation and memory management issues, with direct implications for software reliability and system availability.
The operational impact of this vulnerability extends beyond simple service disruption, as it creates opportunities for attackers to systematically destabilize applications that rely on GraphicsMagick for image processing. When exploited, the assertion failure causes the target application to terminate abruptly, potentially leading to complete service unavailability for legitimate users. This vulnerability particularly affects web applications, content management systems, and any software platforms that accept user-uploaded image files without proper sanitization. The remote nature of the attack means that malicious actors can trigger the vulnerability from anywhere on the network, making it a significant concern for publicly accessible systems. The flaw demonstrates poor defensive programming practices where the code assumes certain memory structures will always contain valid references without proper null checks or error handling mechanisms.
From a cybersecurity perspective, this vulnerability aligns with several ATT&CK framework techniques including TA0043 (Reconnaissance) and TA0045 (Security Deception) as attackers may discover this weakness through routine scanning or testing. The vulnerability also maps to CWE-476 which specifically addresses NULL pointer dereference conditions, highlighting the fundamental programming error that enables this attack vector. Organizations utilizing GraphicsMagick in their image processing pipelines face substantial risk exposure, particularly in environments where automated image handling occurs without proper input validation. The crash condition can be leveraged in distributed denial of service scenarios where multiple targets are simultaneously exploited, amplifying the potential impact. Furthermore, the vulnerability demonstrates the importance of input sanitization and proper error handling in multimedia processing libraries, as these components often serve as attack surfaces for broader exploitation attempts.
Mitigation strategies for CVE-2016-7997 primarily focus on immediate version updates to GraphicsMagick 1.3.26 or later, which contain the necessary patches to address the NULL pointer dereference issue. System administrators should implement comprehensive input validation mechanisms that filter or reject potentially malformed WPG files before they reach the GraphicsMagick processing layer. Network-level protections including firewalls and intrusion detection systems can be configured to monitor for suspicious file upload patterns that may indicate exploitation attempts. Additionally, application developers should incorporate defensive programming practices such as null pointer checks, proper memory management, and robust error handling within their own code when interfacing with GraphicsMagick. Regular security audits and vulnerability assessments should be conducted to identify similar issues in other multimedia processing libraries and ensure proper patch management protocols are in place. Organizations may also consider implementing sandboxing techniques for image processing tasks to limit the potential impact of any remaining vulnerabilities in the system.