CVE-2012-4447 in LibTIFF
Summary
by MITRE
Heap-based buffer overflow in tif_pixarlog.c in LibTIFF before 4.0.3 allows remote attackers to cause a denial of service (application crash) and possibly execute arbitrary code via a crafted TIFF image using the PixarLog Compression format.
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Analysis
by VulDB Data Team • 12/19/2021
The vulnerability identified as CVE-2012-4447 represents a critical heap-based buffer overflow in the LibTIFF library's PixarLog compression handling code. This flaw exists in the tif_pixarlog.c file and affects all versions prior to 4.0.3, making it a significant security concern for any system that processes TIFF image files. The vulnerability specifically manifests when the library attempts to decompress TIFF images that utilize the PixarLog compression format, which is a specialized compression method developed for use in Pixar's image processing workflows. The flaw allows attackers to craft malicious TIFF files that can trigger memory corruption during the decompression process.
The technical implementation of this vulnerability stems from inadequate input validation and bounds checking within the PixarLog decompression routine. When a malformed TIFF image containing the PixarLog compression format is processed, the library fails to properly validate the size parameters of the compressed data blocks. This oversight enables an attacker to manipulate the decompression algorithm into allocating insufficient heap memory for the output buffer, subsequently leading to a buffer overflow condition. The overflow occurs in the heap memory space, making it particularly dangerous as it can potentially be exploited to execute arbitrary code or cause a denial of service through application crashes. The vulnerability is classified under CWE-121 as a heap-based buffer overflow, which represents a common class of memory safety issues that have historically led to exploitation in various software systems.
The operational impact of CVE-2012-4447 extends beyond simple denial of service scenarios, as the vulnerability can potentially be leveraged for remote code execution. Systems that automatically process or render TIFF images, including web applications, image processing servers, and document management systems, become vulnerable to this attack vector. The exploitation requires only that an attacker can convince a target system to process a specially crafted TIFF file, which can be achieved through various means such as email attachments, web uploads, or file sharing platforms. This makes the vulnerability particularly dangerous in environments where users can upload arbitrary files or where automated image processing is performed on user-submitted content. The attack surface is broad and includes applications such as image viewers, document converters, and content management systems that rely on LibTIFF for image handling.
Mitigation strategies for CVE-2012-4447 primarily focus on immediate software updates and comprehensive input validation measures. The most effective solution involves upgrading to LibTIFF version 4.0.3 or later, which contains the necessary patches to address the buffer overflow vulnerability. Organizations should prioritize patch management to ensure all systems processing TIFF images are updated with the latest library versions. Additionally, implementing strict input validation and sanitization measures can provide defense-in-depth protection. This includes validating image file headers, checking compression format compatibility, and implementing size limitations for decompressed data. Network-level protections such as content filtering and sandboxing image processing applications can further reduce the risk of exploitation. The vulnerability demonstrates the importance of maintaining up-to-date third-party libraries and implementing robust memory safety practices as outlined in the ATT&CK framework's software exploitation techniques, where heap-based buffer overflows represent a common method for privilege escalation and code execution attacks.