CVE-2018-5772 in Exiv2
Summary
by MITRE
In Exiv2 0.26, there is a segmentation fault caused by uncontrolled recursion in the Exiv2::Image::printIFDStructure function in the image.cpp file. Remote attackers could leverage this vulnerability to cause a denial of service via a crafted tif file.
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Analysis
by VulDB Data Team • 02/02/2023
The vulnerability identified as CVE-2018-5772 represents a critical denial of service weakness within the Exiv2 image processing library version 0.26. This flaw manifests as a segmentation fault that occurs when the Exiv2::Image::printIFDStructure function processes specially crafted TIFF image files. The issue stems from uncontrolled recursive function calls that lead to stack overflow conditions, effectively crashing the application when it attempts to analyze maliciously constructed image metadata structures.
The technical implementation of this vulnerability resides in the image.cpp source file where the printIFDStructure function fails to implement proper recursion depth limits or termination conditions. When processing TIFF files containing malformed IFD (Image File Directory) structures, the function recursively traverses directory entries without adequate bounds checking, causing the call stack to grow exponentially until system resources are exhausted. This recursive traversal pattern creates a classic stack overflow condition that results in immediate application termination and system crash.
From an operational perspective, this vulnerability presents a significant risk to systems that rely on Exiv2 for image metadata processing, particularly in web applications, content management systems, and digital asset management platforms. Attackers can exploit this weakness by crafting malicious TIFF files that contain deeply nested or circular IFD references, enabling them to trigger the segmentation fault remotely without requiring any special privileges or authentication. The impact extends beyond simple service disruption as this vulnerability can affect automated image processing pipelines, leading to cascading failures in content delivery networks and media processing services.
The vulnerability aligns with CWE-674, which specifically addresses uncontrolled recursion in software implementations, and demonstrates characteristics consistent with ATT&CK technique T1499.004 for network denial of service attacks. Organizations utilizing Exiv2 in production environments face substantial risk from this flaw, particularly those that automatically process user-uploaded image files or integrate image metadata parsing into their core workflows. The remote exploitation capability makes this vulnerability particularly dangerous as attackers can trigger the crash from external systems without physical access to the target infrastructure.
Mitigation strategies should prioritize immediate patching of Exiv2 to version 0.27 or later, where the recursive traversal logic has been properly bounded and controlled. System administrators should implement input validation measures that scan for suspicious image file characteristics before processing, particularly focusing on TIFF file structures that exhibit unusual nesting patterns. Additional protective measures include deploying application sandboxing techniques, implementing resource limits on image processing services, and establishing monitoring protocols to detect unusual crash patterns or service disruptions. Network-level protections such as content filtering and image validation proxies can provide additional defense in depth layers, while regular security assessments should verify that no other recursive functions within the library exhibit similar vulnerabilities. The remediation approach should also include updating all dependent applications and services that utilize Exiv2 to ensure comprehensive protection against this and related recursive traversal vulnerabilities.