CVE-2018-16642 in ImageMagick
Summary
by MITRE
The function InsertRow in coders/cut.c in ImageMagick 7.0.7-37 allows remote attackers to cause a denial of service via a crafted image file due to an out-of-bounds write.
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Analysis
by VulDB Data Team • 05/07/2023
The vulnerability identified as CVE-2018-16642 represents a critical denial of service flaw within ImageMagick's image processing library, specifically affecting version 7.0.7-37 and potentially earlier releases. This issue resides in the InsertRow function located within the coders/cut.c file, which is part of ImageMagick's extensive collection of image format coders designed to handle various file formats. The vulnerability manifests when processing specially crafted image files that exploit a memory access violation, leading to system instability and potential service disruption. The flaw demonstrates characteristics consistent with out-of-bounds write conditions that are classified under CWE-787, which represents a common class of memory safety vulnerabilities where programs write data beyond the boundaries of allocated memory regions.
The technical exploitation of this vulnerability occurs when an attacker crafts a malicious image file that, when processed by ImageMagick's InsertRow function, triggers an out-of-bounds write operation. This condition typically arises from inadequate input validation and boundary checking within the image parsing logic. When ImageMagick attempts to insert a row into an image buffer, the function fails to properly validate the row index or buffer size constraints, allowing malicious input to overwrite adjacent memory locations. This type of vulnerability can be particularly dangerous in web applications or services that accept user-uploaded images, as it enables attackers to cause arbitrary program termination or system crashes without requiring execution of malicious code. The vulnerability aligns with ATT&CK technique T1203, which involves the use of system resource consumption to cause denial of service conditions.
The operational impact of CVE-2018-16642 extends beyond simple service disruption, as it can affect any system or application that relies on ImageMagick for image processing tasks. Systems utilizing ImageMagick for image conversion, manipulation, or validation in web applications, content management systems, or digital asset management platforms become vulnerable to this attack vector. The vulnerability is particularly concerning in environments where automated image processing occurs, such as social media platforms, e-commerce sites, or any service that processes user-generated image content. An attacker could leverage this flaw to repeatedly crash image processing services, leading to cascading failures in dependent systems and potentially creating availability issues for legitimate users. The out-of-bounds write condition can also potentially be chained with other vulnerabilities to achieve more severe outcomes, making this a critical concern for system administrators and security professionals managing image processing infrastructure.
Mitigation strategies for CVE-2018-16642 should prioritize immediate patching of affected ImageMagick installations to version 7.0.8-11 or later, which contains the necessary fixes for this vulnerability. Organizations should implement comprehensive input validation and sanitization measures for all image files processed through ImageMagick, including size and format validation before any processing occurs. Network-level protections such as rate limiting and file type restrictions can help reduce the attack surface by limiting the ability of attackers to submit malicious files. Additionally, implementing proper memory protection mechanisms and using address space layout randomization can help mitigate the potential impact of exploitation attempts. Security monitoring should include detection of abnormal processing patterns or service disruptions that might indicate exploitation attempts. System administrators should also consider implementing sandboxing or containerization techniques to isolate image processing operations and limit potential damage from successful exploitation attempts. The vulnerability underscores the importance of regular security updates and proper input validation practices as fundamental defensive measures against memory safety vulnerabilities.