CVE-2017-9142 in ImageMagick
Summary
by MITRE
In ImageMagick 7.0.5-7 Q16, a crafted file could trigger an assertion failure in the WriteBlob function in MagickCore/blob.c because of missing checks in the ReadOneJNGImage function in coders/png.c.
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Analysis
by VulDB Data Team • 12/07/2022
The vulnerability identified as CVE-2017-9142 represents a critical assertion failure within ImageMagick's image processing pipeline that stems from inadequate input validation mechanisms. This flaw exists specifically in ImageMagick version 7.0.5-7 Q16 and manifests when processing maliciously crafted image files that exploit a weakness in the ReadOneJNGImage function located within the coders/png.c module. The core issue arises from the absence of proper boundary checks and validation logic that should occur during the reading process of JNG (JPEG Network Graphics) image formats, creating an exploitable condition that can lead to denial of service or potentially more severe consequences depending on the execution context.
The technical exploitation of this vulnerability occurs through the manipulation of image file structures that cause the WriteBlob function in MagickCore/blob.c to encounter an assertion failure. This assertion failure is directly triggered by the missing validation checks that should occur within the ReadOneJNGImage function, which processes JNG image data. When a crafted file is processed, the function fails to properly validate the input data before attempting to write it to a blob structure, resulting in an assertion that terminates the application or causes unexpected behavior. The flaw demonstrates a classic case of insufficient input validation where the system assumes valid data without proper verification mechanisms, creating a path for malicious input to disrupt normal operation.
The operational impact of CVE-2017-9142 extends beyond simple denial of service scenarios, as it represents a potential vector for more sophisticated attacks within environments where ImageMagick is used for automated image processing. Systems that automatically process user-uploaded images or handle image manipulation tasks become vulnerable to this assertion failure, potentially allowing attackers to cause application crashes or system instability. This vulnerability particularly affects web applications, content management systems, and any platform that relies on ImageMagick for image handling operations, as these environments often process untrusted input from external sources without proper sanitization.
From a security standards perspective, this vulnerability aligns with CWE-129, which addresses insufficient input validation, and demonstrates characteristics consistent with CWE-682, concerning incorrect arithmetic operations that can lead to assertion failures. The flaw also maps to ATT&CK technique T1203, which involves exploitation of software vulnerabilities for denial of service, and potentially T1059 if the system allows arbitrary code execution through more advanced exploitation techniques. Organizations implementing ImageMagick for image processing should consider this vulnerability as part of their broader security posture assessment, particularly in environments where automated processing of untrusted content occurs.
Mitigation strategies for CVE-2017-9142 require immediate patching of affected ImageMagick installations to version 7.0.5-8 or later, which contains the necessary fixes for the missing validation checks in the ReadOneJNGImage function. Additionally, organizations should implement input validation measures such as file type checking, size limitations, and sandboxed processing environments to reduce the impact of potential exploitation attempts. Network-based mitigations including content filtering and web application firewalls can help detect and prevent malicious image files from reaching vulnerable systems, while regular security assessments should verify that all image processing components are properly updated and configured to prevent similar vulnerabilities from occurring in the future.