CVE-2023-0800: Libtiff Out-of-Bounds Write DoS Vulnerability

CVE-2023-0800 Overview

CVE-2023-0800 is an out-of-bounds write vulnerability affecting LibTIFF version 4.4.0. The flaw exists in the tiffcrop utility, specifically within tools/tiffcrop.c at line 3502. Attackers can exploit this vulnerability to cause a denial-of-service condition by crafting a malicious TIFF file that triggers the out-of-bounds write when processed by the vulnerable application.

Critical Impact

Processing a specially crafted TIFF file can cause application crashes and denial-of-service, potentially disrupting workflows that rely on LibTIFF for image processing operations.

Affected Products

• LibTIFF 4.4.0
• Applications and systems using vulnerable LibTIFF versions
• Linux distributions shipping affected LibTIFF packages (Debian, Gentoo, and others)

Discovery Timeline

• 2023-02-13 - CVE-2023-0800 published to NVD
• 2025-03-21 - Last updated in NVD database

Technical Details for CVE-2023-0800

Vulnerability Analysis

This vulnerability is classified as CWE-787 (Out-of-Bounds Write), a memory corruption issue where the application writes data past the boundaries of allocated memory. The flaw resides in the tiffcrop tool, which is used for cropping, extracting, and manipulating regions of TIFF images. When processing a specially crafted TIFF file, the application fails to properly validate boundaries before performing write operations, leading to memory corruption.

The attack requires local access and user interaction—specifically, a user must process the malicious TIFF file using the tiffcrop utility. While this limits the attack surface compared to network-exploitable vulnerabilities, it remains a significant concern in environments where TIFF files are processed from untrusted sources, such as document management systems, image processing pipelines, or media conversion workflows.

Root Cause

The root cause is improper bounds checking in the tiffcrop.c source file at line 3502. When the tiffcrop utility processes TIFF image data, it performs write operations without adequately validating that the destination buffer can accommodate the data being written. A maliciously crafted TIFF file can specify dimensions or metadata that cause the application to write beyond the allocated buffer boundaries.

Attack Vector

The attack vector is local, requiring an attacker to deliver a crafted TIFF file to a target system and convince a user or automated process to process it with tiffcrop. Attack scenarios include:

The vulnerability is triggered when the malicious TIFF file is opened by the tiffcrop tool. The crafted file contains manipulated image dimensions or structure that causes the out-of-bounds write condition during processing. For detailed technical information about the vulnerability mechanism, refer to the GitLab Issue Discussion.

Detection Methods for CVE-2023-0800

Indicators of Compromise

• Unexpected crashes or segmentation faults when running tiffcrop on TIFF files
• Core dumps generated by LibTIFF-dependent applications during image processing
• Abnormal memory consumption patterns in processes handling TIFF files
• Error logs indicating memory access violations in tiffcrop.c

Detection Strategies

• Monitor for crashes in tiffcrop and related LibTIFF utilities using system logging and crash reporting tools
• Implement file integrity monitoring for TIFF files entering the environment from external sources
• Deploy application sandboxing to contain potential exploitation attempts and detect anomalous behavior
• Use memory safety tools (AddressSanitizer, Valgrind) in development and testing environments to identify exploitation attempts

Monitoring Recommendations

• Enable verbose logging for image processing workflows to capture TIFF file handling events
• Monitor system logs for repeated application crashes associated with LibTIFF utilities
• Implement alerting for unusual patterns of TIFF file processing failures
• Track LibTIFF version information across systems to identify vulnerable deployments

How to Mitigate CVE-2023-0800

Immediate Actions Required

• Update LibTIFF to a patched version that includes commit 33aee127
• Apply distribution-specific security updates from Debian, Gentoo, or your Linux distribution
• Restrict access to tiffcrop utility to trusted users only
• Validate and sanitize TIFF files from untrusted sources before processing

Patch Information

The fix for this vulnerability is available in commit 33aee1275d9d1384791d2206776eb8152d397f00. Users compiling LibTIFF from sources should apply this commit or update to a version containing the fix. Multiple Linux distributions have released security advisories and patches:

• Debian Security Announcement DSA-5361
• Debian LTS Announcement
• Gentoo GLSA-202305-31
• NetApp Security Advisory

Workarounds

• Avoid processing TIFF files from untrusted or unknown sources until patches are applied
• Run tiffcrop in a sandboxed environment or container with restricted permissions
• Implement input validation for TIFF files before passing them to LibTIFF utilities
• Consider using alternative image processing tools for untrusted TIFF files until the vulnerability is patched

# Check LibTIFF version
tiffinfo -v

# Update LibTIFF on Debian/Ubuntu
sudo apt update && sudo apt upgrade libtiff-tools libtiff5

# Update LibTIFF on Gentoo
sudo emerge --sync && sudo emerge -uDN media-libs/tiff