CVE-2016-7535 in ImageMagick
Summary
by MITRE
coders/psd.c in ImageMagick allows remote attackers to cause a denial of service (out-of-bounds write) via a crafted PSD file.
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Analysis
by VulDB Data Team • 12/05/2024
The vulnerability identified as CVE-2016-7535 represents a critical out-of-bounds write flaw within the ImageMagick image processing library, specifically in the psd.c file responsible for handling Photoshop Document format files. This vulnerability exists within the core image manipulation functionality that processes various graphic file formats, making it particularly dangerous as it can be exploited through routine image processing operations. The flaw allows remote attackers to craft malicious PSD files that trigger memory corruption when the library attempts to parse and render these specially constructed images. Such attacks can be delivered through web applications, email attachments, or any system that processes image files without proper validation, creating a wide attack surface that extends across multiple threat vectors.
The technical implementation of this vulnerability stems from insufficient input validation and boundary checking within the PSD file parser. When ImageMagick encounters a crafted PSD file, the parser fails to properly validate array indices or buffer limits during the decompression and rendering process, leading to memory writes that occur beyond the allocated buffer boundaries. This type of flaw falls under the CWE-787 weakness category, which specifically addresses out-of-bounds write conditions that can result in arbitrary code execution or system instability. The vulnerability demonstrates characteristics consistent with memory safety issues commonly found in C/C++ applications where buffer management and input validation are inadequate, particularly in complex multimedia processing libraries that handle numerous file formats with varying structures and encoding methods.
The operational impact of CVE-2016-7535 extends far beyond simple denial of service, as it represents a potential gateway for more severe attacks within systems that process untrusted image content. Remote attackers can leverage this vulnerability to crash applications that use ImageMagick, potentially leading to service disruption across web servers, content management systems, and image processing pipelines. In environments where automatic image processing occurs, such as social media platforms, e-commerce sites, or document management systems, this vulnerability could enable attackers to systematically disrupt services by uploading malicious PSD files. The vulnerability also aligns with ATT&CK technique T1203, which involves legitimate programs being used for defense evasion and system disruption, as the exploitation can occur through normal application workflows without requiring specialized attack tools.
Mitigation strategies for CVE-2016-7535 should focus on immediate patching of affected ImageMagick installations, as the vulnerability was resolved through proper boundary checking and input validation in subsequent releases. Organizations should implement strict file format validation at ingress points, particularly for web applications that accept user-uploaded images, ensuring that all image processing operations occur within secure sandboxes or containers. Network-level controls such as content filtering and file type validation can provide additional defense in depth, while monitoring systems should be configured to detect unusual processing patterns that might indicate exploitation attempts. The vulnerability highlights the importance of adhering to secure coding practices and implementing comprehensive input validation, particularly for libraries that handle complex binary formats and multimedia content, as these systems often become targets for sophisticated attacks due to their widespread use and the complexity of their parsing logic.