CVE-2012-2814 in libexif
Summary
by MITRE
Buffer overflow in the exif_entry_format_value function in exif-entry.c in the EXIF Tag Parsing Library (aka libexif) 0.6.20 allows remote attackers to cause a denial of service or possibly execute arbitrary code via crafted EXIF tags in an image.
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Analysis
by VulDB Data Team • 12/06/2021
The vulnerability identified as CVE-2012-2814 represents a critical buffer overflow flaw within the EXIF Tag Parsing Library commonly known as libexif version 0.6.20. This library serves as a fundamental component for parsing and processing EXIF metadata embedded within digital images, particularly those in jpeg format. The flaw exists specifically within the exif_entry_format_value function located in the exif-entry.c source file, making it a prime target for exploitation by malicious actors seeking to manipulate image processing applications that rely on this library.
The technical nature of this vulnerability stems from improper bounds checking within the exif_entry_format_value function, which processes EXIF tag values during image parsing operations. When encountering malformed or crafted EXIF tags, the function fails to validate the length of incoming data against allocated buffer space, creating a condition where arbitrary amounts of data can be written beyond the intended memory boundaries. This buffer overflow scenario presents multiple attack vectors since it can potentially lead to either denial of service through application crashes or more severely, arbitrary code execution when the overflow corrupts program execution flow. The vulnerability is particularly dangerous because EXIF metadata is automatically processed by many image viewing and editing applications without user intervention, making exploitation possible through simple image file manipulation.
The operational impact of CVE-2012-2814 extends across numerous digital imaging applications that depend on libexif for metadata handling, including web browsers, image viewers, photo management software, and content management systems. Attackers can craft malicious image files containing specially formatted EXIF tags that trigger the buffer overflow when the library attempts to parse them during normal image processing operations. This creates a significant risk for web applications that allow user-uploaded images, as attackers could potentially compromise systems by uploading malicious images that cause applications to crash or execute unintended code. The vulnerability aligns with CWE-121, which categorizes buffer overflow conditions as critical memory safety issues, and represents a classic example of how metadata parsing can become an attack surface for remote code execution.
From a threat modeling perspective, this vulnerability maps directly to several ATT&CK techniques including T1203 (Exploitation for Client Execution) and T1059 (Command and Scripting Interpreter) as attackers can leverage the overflow to execute arbitrary code on vulnerable systems. The attack surface is particularly broad since many applications automatically parse EXIF data without user interaction, making it difficult to prevent exploitation through user awareness alone. Security professionals should consider implementing input validation at multiple layers, including application-level sanitization of EXIF data and deployment of intrusion detection systems monitoring for suspicious image file processing patterns. The remediation strategy involves updating to libexif versions that contain patched implementations of the exif_entry_format_value function, along with implementing proper bounds checking and memory management practices to prevent similar vulnerabilities in future development cycles. Organizations should also consider implementing sandboxing mechanisms for image processing operations and establishing robust patch management procedures to ensure timely deployment of security updates across all affected systems.