CVE-2024-7006: Null Pointer Dereference Vulnerability in Libtiff Leads to Denial of Service Attacks

A new vulnerability has been discovered in Libtiff, a widely-used library for reading and writing Tagged Image File Format (TIFF) images. The vulnerability, tracked as CVE-2024-7006, is related to a null pointer dereference flaw and can be exploited by malicious hackers to cause memory allocation failures, segmentation faults, and ultimately crash the vulnerable application, resulting in a denial of service (DoS) attack.

Technical Analysis

The null pointer dereference flaw lies in the tif_dirinfo.c source file, and it stems from the incorrect handling of certain memory pointers. In essence, the vulnerable code may attempt to reference a memory location associated with a null pointer, causing an unexpected application behavior that might lead to memory allocation failures and, eventually, application crashes.

Here's a simplified code snippet to help illustrate the problem

#include "tiffio.h"

void vulnerable_function(TIFF* tif) {
    TIFFDirEntry* entry = NULL;
    ...
    if (condition) {
        entry = (TIFFDirEntry*) _TIFFmalloc(n * sizeof(TIFFDirEntry));
        if (!entry) {
            return; // Memory allocation failed
        }
    }
    ...
    // The following line dereferences a potentially null pointer
    entry->tdir_offset = some_value; // Possible null pointer dereference
    ...
}

In this example, if a memory allocation failure occurs, the function will return prematurely, leaving the entry pointer uninitialized (i.e., equal to NULL). Later on, the code attempts to dereference this potentially null pointer, which can result in a segmentation fault.

Exploit Details

An attacker may exploit this vulnerability by crafting a malicious TIFF image file designed to trigger the null pointer dereference flaw. If a targeted application, which uses the vulnerable Libtiff library, attempts to read or write this malicious TIFF image, it could cause a memory allocation failure and a subsequent segmentation fault, crashing the application and creating a denial-of-service situation.

Mitigation

Users are advised to update their Libtiff installations to the latest version available that addresses this vulnerability. Additionally, application developers should validate and sanitize input data to minimize the risk of successfully exploiting this flaw.

Original References

1. Libtiff official website: http://libtiff.org/
2. The CVE-2024-7006 advisory: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-7006
3. The technical analysis of the vulnerability from the researchers who discovered it: [Link to the researcher's website or document]

Conclusion

CVE-2024-7006 is a critical null pointer dereference vulnerability found in the widely-used Libtiff library. To safeguard against potential DoS attacks resulting from this vulnerability, users should update their Libtiff libraries and application developers should be diligent in validating and sanitizing input data while handling TIFF images. Staying up-to-date with software patches and adopting security best practices can greatly reduce the risks associated with such vulnerabilities.

Timeline

Published on: 08/12/2024 13:38:40 UTC
Last modified on: 11/06/2024 10:15:04 UTC