CVE-2017-11522 in ImageMagick
Summary
by MITRE
The WriteOnePNGImage function in coders/png.c in ImageMagick through 6.9.9-0 and 7.x through 7.0.6-1 allows remote attackers to cause a denial of service (NULL pointer dereference) via a crafted file.
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Analysis
by VulDB Data Team • 12/13/2022
The vulnerability identified as CVE-2017-11522 represents a critical denial of service weakness within ImageMagick's image processing library, specifically affecting the WriteOnePNGImage function located in the coders/png.c file. This flaw exists in ImageMagick versions through 6.9.9-0 and 7.x through 7.0.6-1, making it a widespread issue affecting numerous systems that rely on this popular image manipulation software. The vulnerability stems from inadequate input validation and error handling within the PNG image writing process, creating a scenario where maliciously crafted image files can trigger unexpected behavior in the application.
The technical exploitation of this vulnerability occurs through a NULL pointer dereference condition that manifests when the WriteOnePNGImage function processes specially crafted PNG files. When ImageMagick attempts to write a PNG image with malformed or maliciously constructed data, the function fails to properly validate pointer references before dereferencing them, resulting in a crash of the application. This type of vulnerability falls under CWE-476 which specifically addresses NULL pointer dereference issues, where the software attempts to access memory through a pointer that has not been properly initialized or has been set to NULL. The flaw essentially creates a situation where legitimate image processing operations become impossible due to the application's failure to handle malformed input gracefully.
From an operational standpoint, this vulnerability presents significant risks for systems that process user-uploaded images or handle image data from untrusted sources. Remote attackers can leverage this weakness to disrupt services by sending specially crafted PNG files that cause ImageMagick-based applications to crash, effectively creating a denial of service condition. The impact extends beyond simple application crashes as it can affect web applications, content management systems, and any platform that utilizes ImageMagick for image processing. This vulnerability particularly affects systems that automatically process or convert images, such as social media platforms, e-commerce sites, and file sharing services where users can upload various image formats. The ATT&CK framework categorizes this type of vulnerability under the T1499.004 technique for Network Denial of Service, as it allows adversaries to consume system resources or cause service disruption through crafted inputs.
Organizations affected by this vulnerability should implement immediate mitigations including updating to patched versions of ImageMagick where available, implementing input validation measures to filter out suspicious image files, and configuring application-level restrictions to limit image processing operations. The recommended remediation strategy involves upgrading to ImageMagick versions that have addressed this specific NULL pointer dereference issue, typically versions 6.9.9-1 and 7.0.6-2 or later. Additionally, system administrators should consider implementing sandboxing techniques to isolate image processing operations and employ strict file type validation to prevent malicious files from reaching the vulnerable code paths. Network-level protections such as rate limiting and content filtering can also help mitigate the impact of exploitation attempts while the software is being updated.