CVE-2014-9763 in imlib2
Summary
by MITRE
imlib2 before 1.4.7 allows remote attackers to cause a denial of service (divide-by-zero error and application crash) via a crafted PNM file.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 08/19/2022
The vulnerability identified as CVE-2014-9763 affects the imlib2 library version 1.4.7 and earlier, representing a critical denial of service weakness that can be exploited remotely through maliciously crafted PNM image files. This issue specifically targets the image processing capabilities of applications that rely on imlib2 for handling portable anymap (PNM) format images, which encompasses PBM, PGM, and PPM file types. The vulnerability manifests when the library processes malformed PNM files that contain invalid mathematical operations, particularly division by zero conditions that are not properly handled within the parsing logic.
The technical flaw resides in the imlib2 library's insufficient input validation mechanisms when processing PNM file headers and data structures. When a malicious PNM file contains crafted values that result in division by zero during the image parsing process, the application crashes due to unhandled arithmetic exceptions. This occurs because the library fails to implement proper bounds checking and mathematical operation validation before executing calculations on image metadata. The vulnerability is classified as a divide-by-zero error under CWE-369, which represents a specific weakness in input validation where mathematical operations are performed without proper error handling for zero denominators.
The operational impact of this vulnerability extends beyond simple application crashes, as it can be leveraged by remote attackers to disrupt services that depend on imlib2 for image processing. Applications such as web servers, image viewers, and content management systems that accept user-uploaded PNM files become vulnerable to this attack vector. The vulnerability is particularly concerning in web environments where users can upload arbitrary image files, as attackers can craft malicious PNM files that will cause the hosting application to crash whenever the image is processed or displayed. This can lead to complete service disruption and potential denial of service for legitimate users.
Mitigation strategies for CVE-2014-9763 primarily involve updating to imlib2 version 1.4.7 or later, which includes proper input validation and error handling for mathematical operations during PNM file processing. System administrators should also implement additional security measures such as input sanitization, file type validation, and content scanning for uploaded images to prevent malicious files from reaching the processing layer. The ATT&CK framework categorizes this vulnerability under the T1499.004 technique for "Network Denial of Service" as it can be exploited to cause service disruption through application crashes. Organizations should also consider implementing network segmentation and monitoring for unusual application crash patterns that could indicate exploitation attempts, as this vulnerability represents a classic example of how malformed input can be weaponized for denial of service attacks.