CVE-2006-0405 in libtiff
Summary
by MITRE
The TIFFFetchShortPair function in tif_dirread.c in libtiff 3.8.0 allows remote attackers to cause a denial of service (application crash) via a crafted TIFF image that triggers a NULL pointer dereference, possibly due to changes in type declarations and/or the TIFFVSetField function.
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Analysis
by VulDB Data Team • 06/20/2019
The vulnerability identified as CVE-2006-0405 represents a critical denial of service flaw within the libtiff library version 3.8.0, specifically affecting the TIFFFetchShortPair function located in the tif_dirread.c source file. This issue manifests when processing specially crafted TIFF image files that exploit a NULL pointer dereference condition, leading to application crashes and potential system instability. The vulnerability stems from inadequate input validation and error handling within the image parsing mechanism, where the function fails to properly validate pointer references before dereferencing them during TIFF directory reading operations. The flaw is particularly concerning because it can be triggered remotely through the processing of malicious TIFF files, making it a significant threat to applications that rely on libtiff for image handling.
The technical implementation of this vulnerability involves a cascade of memory management issues that originate from improper type declaration handling within the TIFFVSetField function and its interaction with TIFFFetchShortPair. When a malicious TIFF file is processed, the parsing logic encounters malformed directory entries that cause the TIFFFetchShortPair function to attempt dereferencing a NULL pointer, resulting in immediate application termination. This type of vulnerability falls under CWE-476 which specifically addresses NULL pointer dereference conditions, and it aligns with ATT&CK technique T1499.001 which covers network denial of service attacks through application-level vulnerabilities. The flaw demonstrates poor defensive programming practices where the software fails to implement proper null checks before accessing memory references, creating an exploitable condition that adversaries can leverage.
The operational impact of CVE-2006-0405 extends beyond simple application crashes to potentially disrupt critical services that depend on TIFF image processing capabilities. Systems running applications using vulnerable libtiff versions may experience unexpected service interruptions when processing untrusted image files, creating cascading failures in document management systems, image servers, and digital asset management platforms. The vulnerability affects a wide range of software ecosystems including web applications, content management systems, and image processing pipelines that utilize libtiff for TIFF file handling. Organizations may face significant downtime and operational disruption as attackers can systematically exploit this weakness to cause service degradation, particularly in environments where automated image processing workflows are prevalent.
Mitigation strategies for this vulnerability require immediate patching of affected libtiff installations to version 3.8.1 or later, which contains the necessary fixes for the NULL pointer dereference condition. System administrators should implement comprehensive input validation measures that sanitize all TIFF file inputs before processing, including implementing file format validation and size restrictions. Network-level protections such as content filtering and sandboxing mechanisms can provide additional layers of defense by preventing malicious TIFF files from reaching vulnerable applications. Security monitoring should include detection of unusual application crash patterns and memory access violations that may indicate exploitation attempts. Organizations should also consider implementing principle of least privilege access controls for image processing services and regularly audit their software dependencies to identify other potential vulnerabilities. The fix addresses the underlying issue by implementing proper null pointer checks and ensuring that the TIFFVSetField function correctly handles type declarations before passing data to TIFFFetchShortPair, thereby preventing the exploitable condition that led to the denial of service scenario.