CVE-2024-7006: Libtiff Null Pointer Dereference DOS Flaw

CVE-2024-7006 Overview

A null pointer dereference vulnerability has been discovered in Libtiff via tif_dirinfo.c. This flaw allows an attacker to trigger memory allocation failures through certain means, such as restricting the heap space size or injecting faults, causing a segmentation fault. This can cause an application crash, eventually leading to a denial of service condition.

Critical Impact

Applications processing TIFF images using vulnerable Libtiff versions are susceptible to denial of service attacks through crafted inputs that trigger null pointer dereference conditions.

Affected Products

• Libtiff Libtiff (all versions prior to patch)
• Red Hat Enterprise Linux 8.0 and 9.0
• Red Hat Enterprise Linux for ARM 64 9.2
• Red Hat Enterprise Linux for Power Little Endian EUS 9.2
• Red Hat Enterprise Linux Server AUS 9.2

Discovery Timeline

• 2024-08-12 - CVE CVE-2024-7006 published to NVD
• 2025-11-03 - Last updated in NVD database

Technical Details for CVE-2024-7006

Vulnerability Analysis

This vulnerability is classified as a Null Pointer Dereference (CWE-476). The flaw resides within the tif_dirinfo.c file of the Libtiff library, which is responsible for handling TIFF directory information. When certain memory allocation operations fail, the code does not properly validate whether the returned pointer is valid before dereferencing it. This lack of null pointer checking creates an exploitable condition where an attacker can force the application into an unrecoverable crash state.

The attack can be executed remotely over a network without requiring any privileges or user interaction. While the vulnerability does not allow for data exfiltration or modification, it provides a reliable mechanism for denying service to any application that processes TIFF images through the vulnerable Libtiff library.

Root Cause

The root cause of this vulnerability stems from insufficient null pointer validation in tif_dirinfo.c. When memory allocation fails—whether due to resource exhaustion, heap space restrictions, or fault injection—the code proceeds to use the returned pointer without first verifying that the allocation was successful. This programming error allows an attacker to craft conditions that cause the memory allocation to fail, resulting in a null pointer being dereferenced and causing a segmentation fault.

Attack Vector

An attacker can exploit this vulnerability remotely by causing memory allocation failures in applications that use Libtiff to process TIFF images. The attack does not require authentication or user interaction, making it particularly dangerous for web services or applications that automatically process user-uploaded images. The attacker can trigger the vulnerability through various means including restricting heap space size or injecting faults during image processing operations.

The vulnerability manifests when the tif_dirinfo.c component attempts to dereference a pointer that was expected to point to allocated memory but instead contains a null value due to allocation failure. For technical details on the specific code path, see the Red Hat Bug Report #2302996.

Detection Methods for CVE-2024-7006

Indicators of Compromise

• Application crashes or segmentation faults when processing TIFF images
• Abnormal memory allocation patterns in Libtiff-dependent applications
• Repeated service restarts or availability issues in image processing services
• Core dump files indicating null pointer dereference in tif_dirinfo.c

Detection Strategies

• Monitor system logs for segmentation fault messages related to Libtiff or TIFF processing
• Implement application-level crash monitoring for services that process TIFF images
• Deploy file integrity monitoring on Libtiff library files to detect unauthorized modifications
• Use vulnerability scanners to identify systems running vulnerable Libtiff versions

Monitoring Recommendations

• Enable crash reporting and core dump analysis for image processing applications
• Monitor resource utilization patterns that may indicate attempted exploitation
• Set up alerts for repeated application crashes in TIFF processing workflows
• Review system audit logs for unusual patterns in memory allocation failures

How to Mitigate CVE-2024-7006

Immediate Actions Required

• Update Libtiff to the latest patched version available from your distribution
• Apply Red Hat security advisories RHSA-2024:6360, RHSA-2024:8833, and RHSA-2024:8914 for affected RHEL systems
• Audit systems to identify all applications using Libtiff for TIFF processing
• Implement input validation and resource limits for TIFF file processing

Patch Information

Multiple vendors have released security patches to address this vulnerability:

• Red Hat: Security advisories RHSA-2024:6360, RHSA-2024:8833, and RHSA-2024:8914 provide patches for Enterprise Linux
• Debian: Debian LTS announcement addresses this vulnerability
• NetApp: Security advisory ntap-20240920-0001 provides guidance for affected products

Workarounds

• Implement resource limits and memory constraints for TIFF processing applications
• Isolate TIFF processing in sandboxed environments to contain crash impacts
• Deploy rate limiting on services that accept TIFF files to reduce attack surface
• Consider using alternative image libraries where Libtiff functionality is not critical

# Example: Update libtiff on RHEL/CentOS systems
sudo yum update libtiff

# Example: Verify installed libtiff version
rpm -qa | grep libtiff

# Example: Check for Debian/Ubuntu systems
sudo apt-get update && sudo apt-get upgrade libtiff5