CVE-2018-9304 in Exiv2
Summary
by MITRE
In Exiv2 0.26, a divide by zero in BigTiffImage::printIFD in bigtiffimage.cpp could result in denial of service.
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Analysis
by VulDB Data Team • 02/27/2023
The vulnerability identified as CVE-2018-9304 resides within the Exiv2 library version 0.26, specifically within the BigTiffImage::printIFD function located in the bigtiffimage.cpp source file. This issue represents a critical divide by zero error that occurs when processing certain malformed TIFF image files, particularly those that utilize the BigTIFF format. The flaw demonstrates characteristics consistent with CWE-369, which addresses the division by zero weakness in software systems. Exiv2 is widely used for reading and writing image metadata across numerous applications and operating systems, making this vulnerability particularly concerning from a security perspective.
The technical implementation of this vulnerability involves the processing of image file headers and directory structures where the software attempts to perform division operations without proper validation of the divisor value. When a specially crafted BigTIFF file contains malformed directory entries or incorrect offset values, the BigTiffImage::printIFD function executes a division operation with a zero denominator, causing the application to crash or become unresponsive. This behavior constitutes a classic denial of service condition that can be exploited by malicious actors to disrupt services or applications that rely on Exiv2 for image metadata processing.
The operational impact of CVE-2018-9304 extends beyond simple application crashes, as it can be leveraged in various attack scenarios within the ATT&CK framework's execution and denial of service tactics. Systems that process untrusted image files, such as web applications, content management systems, and digital asset management platforms, become vulnerable to this attack vector. The vulnerability can be particularly dangerous in automated processing environments where batch operations on image files are common, as a single malicious file can cause cascading failures across multiple processes. Network services that accept image uploads or perform metadata extraction operations are especially at risk, as attackers can craft malicious files to trigger the divide by zero condition and render the service unavailable.
Mitigation strategies for this vulnerability require immediate patching of Exiv2 library installations to version 0.27 or later, where the divide by zero condition has been addressed through proper input validation and error handling mechanisms. Organizations should implement comprehensive image file validation processes that include pre-processing checks for malformed file structures before passing files to Exiv2 for metadata extraction. Network segmentation and application whitelisting can provide additional defense-in-depth measures to limit the potential impact of exploitation attempts. Security monitoring should include detection of unusual application crash patterns or denial of service conditions that may indicate exploitation of this vulnerability, aligning with ATT&CK techniques for command and control and execution phases. Regular security assessments of image processing pipelines and dependency management practices are essential to prevent similar vulnerabilities from emerging in other components of the software stack.