CVE-2014-9837 in ImageMagick
Summary
by MITRE
coders/pnm.c in ImageMagick 6.9.0-1 Beta and earlier allows remote attackers to cause a denial of service (crash) via a crafted png file.
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Analysis
by VulDB Data Team • 11/28/2022
The vulnerability identified as CVE-2014-9837 represents a critical denial of service flaw within ImageMagick's Portable Network Graphics (PNG) file processing functionality. This issue affects versions 6.9.0-1 Beta and earlier, where the coders/pnm.c component fails to properly validate input data from maliciously crafted PNG files. The flaw manifests when the image processing library attempts to handle malformed or specially constructed PNG data, leading to a crash condition that can be exploited remotely by attackers. Such vulnerabilities are particularly dangerous in web environments where ImageMagick is commonly used for image processing, as they can be leveraged to disrupt services through simple file uploads or image manipulations.
The technical root cause of this vulnerability stems from insufficient input validation within the PNG decoder implementation. When ImageMagick processes a PNG file, the pnm.c module does not adequately check for malformed data structures or unexpected values in the PNG format specification. This lack of proper boundary checking and data validation creates an exploitable condition where crafted PNG files can trigger memory access violations or buffer overflows. The vulnerability aligns with CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds writes. These weaknesses occur because the code does not properly validate the dimensions, color types, or compression parameters within the PNG file header and subsequent data chunks, allowing attackers to craft inputs that cause the processing engine to access memory beyond allocated boundaries.
The operational impact of CVE-2014-9837 extends beyond simple service disruption, as it can be weaponized in various attack scenarios that target web applications relying on ImageMagick for image handling. In web environments, this vulnerability can be exploited through file upload mechanisms, where an attacker uploads a malicious PNG file that, when processed by the application, causes the ImageMagick library to crash. The crash typically results in a complete service outage or application hang, making it an effective denial of service vector. Attackers can leverage this vulnerability in automated scanning tools or as part of larger attack campaigns targeting vulnerable web applications. This flaw particularly affects content management systems, e-commerce platforms, and any web service that accepts user-uploaded images and processes them using ImageMagick, creating a significant risk to service availability and user experience.
Organizations affected by this vulnerability should implement immediate mitigations including updating to ImageMagick version 6.9.0-1 or later, which contains the necessary patches to address the input validation issues. Additionally, implementing proper input sanitization at the application level can provide defense in depth, where applications validate file types and sizes before passing them to ImageMagick for processing. Network-level controls such as implementing web application firewalls and restricting file upload capabilities to known good formats can help reduce exposure. The vulnerability also aligns with ATT&CK technique T1499.004, which covers network denial of service attacks, and T1595.001, which involves reconnaissance through network scanning. Security teams should also consider implementing monitoring for unusual processing patterns that might indicate exploitation attempts, as well as regular vulnerability assessments to identify other potential weaknesses in image processing pipelines.