CVE-2018-9018 in GraphicsMagick
Summary
by MITRE
In GraphicsMagick 1.3.28, there is a divide-by-zero in the ReadMNGImage function of coders/png.c. Remote attackers could leverage this vulnerability to cause a crash and denial of service via a crafted mng file.
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Analysis
by VulDB Data Team • 02/24/2023
The vulnerability identified as CVE-2018-9018 represents a critical divide-by-zero error within the GraphicsMagick image processing library version 1.3.28. This flaw exists specifically within the ReadMNGImage function located in the coders/png.c source file, making it a targeted issue affecting multimedia file handling capabilities. The vulnerability stems from improper input validation when processing Multiple Network Graphics format files, which are commonly used for animations and complex image compositions. Attackers can exploit this weakness by crafting malicious MNG files that trigger the division operation by zero during image parsing, leading to immediate program termination and system instability.
The technical execution of this vulnerability demonstrates a classic software error pattern where mathematical operations lack proper boundary checks or input sanitization. When GraphicsMagick attempts to parse a specially crafted MNG file, the ReadMNGImage function encounters a scenario where a division operation attempts to divide by zero, causing an arithmetic exception that terminates the application process. This type of error falls under CWE-369, which specifically addresses divide-by-zero conditions in software implementations. The vulnerability operates at the application layer, requiring no special privileges or system access, making it particularly dangerous for web applications or services that process user-uploaded images.
From an operational impact perspective, this vulnerability creates significant denial of service risks for systems relying on GraphicsMagick for image processing tasks. Remote attackers can reliably crash services by uploading or accessing malicious MNG files, potentially disrupting availability for legitimate users. The exploitability of this vulnerability aligns with ATT&CK technique T1499.004, which covers network denial of service attacks through application layer exploitation. Systems that process untrusted image content, such as content management systems, social media platforms, or image hosting services, face high risk exposure. The vulnerability's remote exploitability means that attackers do not need physical access or network proximity to cause service disruption.
Mitigation strategies for CVE-2018-9018 should prioritize immediate patching of GraphicsMagick installations to version 1.3.29 or later, which contains the necessary fixes for the divide-by-zero condition. Organizations should implement input validation and sanitization measures for all image file processing pipelines, including MIME type verification and file format checking before processing. Network segmentation and access controls can limit the impact of successful exploitation attempts, while monitoring systems should be configured to detect unusual application termination patterns. Additionally, implementing sandboxed processing environments for image handling can contain potential exploitation attempts and prevent cascading failures across system components. Security teams should also consider deploying automated vulnerability scanning tools to identify and remediate similar issues in other image processing libraries and applications within their infrastructure.