CVE-2005-4676 in Exiv2
Summary
by MITRE
Buffer overflow in Andreas Huggel Exiv2 before 0.9 does not null terminate strings before calling the sscanf function, which allows remote attackers to cause a denial of service (application crash) via images with crafted IPTC metadata.
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Analysis
by VulDB Data Team • 01/19/2025
The vulnerability identified as CVE-2005-4676 represents a critical buffer overflow condition within the Exiv2 library version 0.9 and earlier, developed by Andreas Huggel. This flaw specifically manifests in the handling of IPTC metadata within image files, creating a pathway for remote attackers to exploit the application through carefully crafted image content. The issue stems from improper string handling practices that fail to ensure null termination before processing with the sscanf function, a common pattern that has been extensively documented in cybersecurity literature as a primary vector for memory corruption exploits.
The technical implementation of this vulnerability involves the Exiv2 library's parsing mechanism for IPTC metadata fields within image files. When processing IPTC data, the library does not properly null terminate character strings before invoking the sscanf function, which expects null-terminated input. This omission creates a scenario where the sscanf function reads beyond its intended buffer boundaries, potentially overwriting adjacent memory locations. The flaw operates under the Common Weakness Enumeration classification as CWE-121, which encompasses stack-based buffer overflow conditions, and more specifically aligns with CWE-122, heap-based buffer overflow patterns that can occur when memory management is insufficient.
The operational impact of this vulnerability extends beyond simple denial of service conditions, as the application crash resulting from the buffer overflow can be leveraged by attackers to potentially execute arbitrary code or cause system instability. Remote attackers can craft specially formatted image files containing malicious IPTC metadata that, when processed by vulnerable applications using Exiv2, triggers the buffer overflow condition. This creates a significant risk for web applications, content management systems, and any software platforms that process user-uploaded images without proper input validation. The vulnerability demonstrates the critical importance of proper input sanitization and memory boundary checking in multimedia processing libraries that handle metadata within binary file formats.
Mitigation strategies for this vulnerability require immediate patching of affected Exiv2 versions to 0.9 or later, where the null termination issue has been resolved. System administrators should implement comprehensive input validation mechanisms that verify metadata integrity before processing, particularly for IPTC data within image files. The ATT&CK framework categorizes this vulnerability under T1203, which covers exploitation of remote services and file processing vulnerabilities, making it particularly relevant for defensive measures targeting file upload and processing functions. Organizations should also consider implementing network segmentation and access controls to limit exposure of vulnerable systems, while maintaining regular security assessments to identify similar buffer overflow patterns in other multimedia libraries and processing frameworks.