CVE-2017-11639 in ImageMagick
Summary
by MITRE
When ImageMagick 7.0.6-1 processes a crafted file in convert, it can lead to a heap-based buffer over-read in the WriteCIPImage() function in coders/cip.c, related to the GetPixelLuma function in MagickCore/pixel-accessor.h.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 12/14/2022
The vulnerability identified as CVE-2017-11639 represents a critical heap-based buffer over-read flaw within ImageMagick version 7.0.6-1, specifically manifesting during the processing of maliciously crafted image files through the convert utility. This issue originates from the WriteCIPImage() function located in the coders/cip.c source file, where improper bounds checking allows attackers to manipulate memory access patterns that exceed allocated buffer boundaries. The vulnerability is particularly concerning as it leverages the GetPixelLuma function from MagickCore/pixel-accessor.h, which serves as a fundamental pixel manipulation routine within the image processing pipeline. The flaw occurs when ImageMagick attempts to serialize image data into the CIP format, creating conditions where memory reads extend beyond intended buffer limits, potentially exposing sensitive data or enabling arbitrary code execution depending on memory layout.
The technical exploitation of this vulnerability demonstrates a classic buffer over-read scenario that falls under CWE-125, which specifically addresses out-of-bounds read conditions in software systems. When an attacker crafts a malicious image file with carefully constructed pixel data, the WriteCIPImage() function fails to properly validate input boundaries during the pixel luma calculation process. This allows the GetPixelLuma function to access memory locations that were not allocated for the intended buffer, creating opportunities for information disclosure, system instability, or potentially more severe remote code execution scenarios. The vulnerability is particularly dangerous in environments where ImageMagick processes untrusted user uploads, as it can be triggered through automated image conversion workflows without requiring user interaction.
The operational impact of CVE-2017-11639 extends significantly across various attack vectors and system architectures, as ImageMagick is widely deployed in web applications, content management systems, and automated processing pipelines. The vulnerability can be exploited through multiple attack surfaces including web applications that utilize ImageMagick for image conversion, file upload handlers, and automated image processing services. According to ATT&CK framework category T1059, this vulnerability enables adversaries to execute malicious code through command-line interfaces, while T1203 covers the use of image processing libraries for privilege escalation. Organizations using vulnerable versions of ImageMagick face potential data breaches, system compromise, and denial of service conditions, particularly when processing user-generated content or handling file uploads without proper sanitization.
Mitigation strategies for CVE-2017-11639 require immediate patching of ImageMagick installations to versions 7.0.6-10 or later, which contain the necessary fixes for buffer boundary validation in the WriteCIPImage() function. System administrators should implement strict input validation and sanitization for all file uploads, particularly focusing on image files processed through ImageMagick or similar libraries. Network segmentation and application firewalls can help limit exposure by restricting access to vulnerable image processing endpoints. The principle of least privilege should be enforced when running ImageMagick processes, ensuring that conversion utilities operate with minimal required permissions and in restricted environments. Additionally, implementing automated security scanning tools that can detect and block malicious image files before they reach the processing pipeline provides an additional layer of defense. Organizations should also consider implementing sandboxing techniques for image processing operations and regularly monitoring system logs for suspicious activity related to image conversion processes, as the vulnerability can be triggered through automated exploitation frameworks targeting the specific function call patterns within the affected library versions.