CVE-2014-9655 in LibTIFF
Summary
by MITRE
The (1) putcontig8bitYCbCr21tile function in tif_getimage.c or (2) NeXTDecode function in tif_next.c in LibTIFF allows remote attackers to cause a denial of service (uninitialized memory access) via a crafted TIFF image, as demonstrated by libtiff-cvs-1.tif and libtiff-cvs-2.tif.
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Analysis
by VulDB Data Team • 07/24/2022
The vulnerability identified as CVE-2014-9655 resides within the LibTIFF library, a widely used software library for handling Tagged Image File Format files. This issue affects two distinct functions within the library's codebase: putcontig8bitYCbCr21tile in tif_getimage.c and NeXTDecode in tif_next.c. Both functions demonstrate critical flaws in memory management that can be exploited by remote attackers to trigger denial of service conditions through carefully crafted TIFF image files. The vulnerability specifically manifests when processing malformed image data, creating scenarios where the software attempts to access uninitialized memory regions without proper bounds checking or validation mechanisms.
The technical flaw in these functions stems from inadequate input validation and memory access controls during image decompression processes. When the putcontig8bitYCbCr21tile function processes YCbCr color space data with 8-bit samples and 21 tile configuration, or when the NeXTDecode function handles NeXT image format decoding, the code fails to properly validate the structure and content of incoming TIFF data. This lack of proper boundary checking allows attackers to craft malicious TIFF files that contain malformed data sequences, causing the library to attempt reading from uninitialized memory locations. The vulnerability is classified as an uninitialized memory access issue, which directly maps to CWE-457: Use of Uninitialized Variable, and represents a classic example of memory safety issues that can lead to system instability.
The operational impact of this vulnerability extends beyond simple denial of service, as it can be leveraged to cause application crashes, system instability, and potentially more severe consequences in environments where LibTIFF is used extensively. Systems that process untrusted TIFF images, such as web servers, image processing applications, and document management systems, become vulnerable to exploitation. The attack vector is particularly concerning because it requires no special privileges or authentication, making it accessible to remote attackers who can simply upload or provide a malicious TIFF file to trigger the vulnerability. This aligns with ATT&CK technique T1203: Exploitation for Client Execution, where adversaries exploit vulnerabilities in software to execute arbitrary code or cause service disruption.
The specific demonstration files libtiff-cvs-1.tif and libtiff-cvs-2.tif serve as proof-of-concept examples that showcase how the vulnerability can be triggered through carefully constructed image data. These files contain malformed structures that cause the affected functions to access memory regions that have not been properly initialized, leading to undefined behavior and system instability. Organizations using LibTIFF in their applications should consider this vulnerability as part of their broader security posture assessment, particularly in environments where untrusted image data is processed. The vulnerability highlights the critical importance of input validation and memory safety practices in image processing libraries, as these components often handle sensitive data and are frequently targeted by attackers seeking to exploit memory corruption vulnerabilities. Mitigation strategies should include immediate library updates, implementation of proper input sanitization, and deployment of security monitoring to detect potential exploitation attempts.