CVE-2022-2521 in libtiff
Summary
by MITRE • 08/31/2022
It was found in libtiff 4.4.0rc1 that there is an invalid pointer free operation in TIFFClose() at tif_close.c:131 called by tiffcrop.c:2522 that can cause a program crash and denial of service while processing crafted input.
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Analysis
by VulDB Data Team • 05/26/2026
The vulnerability identified as CVE-2022-2521 affects the libtiff library version 4.4.0rc1 and represents a critical memory corruption issue that can lead to denial of service conditions. This flaw exists within the TIFFClose() function in the tif_close.c file at line 131, where an invalid pointer free operation occurs when processing crafted TIFF input files. The vulnerability is particularly concerning because it can be triggered during normal file processing operations, making it exploitable in various real-world scenarios. The issue manifests when the tiffcrop utility calls TIFFClose() function, which then attempts to free memory that has already been freed or was never properly allocated, creating a classic use-after-free condition that can result in program crashes and system instability.
The technical nature of this vulnerability stems from improper memory management within the libtiff library's file closing routine. When the TIFFClose() function processes certain malformed or crafted input files, it attempts to free memory pointers that are either invalid, already freed, or not properly initialized. This improper memory deallocation can lead to heap corruption, which may cause the application to crash or behave unpredictably. The vulnerability is classified as a use-after-free condition under CWE-416, which specifically addresses the freeing of memory that has already been freed or attempting to access memory that has been deallocated. The flaw occurs in the context of image processing where the tiffcrop utility is designed to handle various TIFF file formats, making it a potential attack vector for adversaries seeking to disrupt services through denial of service attacks.
The operational impact of CVE-2022-2521 extends beyond simple program crashes, as it can be leveraged to create persistent denial of service conditions in systems that rely on libtiff for image processing. Applications that utilize libtiff for TIFF file handling, including image servers, document management systems, and multimedia processing tools, become vulnerable to this attack vector. The vulnerability can be particularly dangerous in automated processing environments where multiple files are processed sequentially, as a single malformed file can cause cascading failures throughout the system. This issue aligns with ATT&CK technique T1499.004, which covers network denial of service attacks through exploitation of software vulnerabilities, and can be used as part of broader attack chains targeting system availability. Systems that process untrusted TIFF input from external sources, such as web applications accepting image uploads or content management systems handling user-generated media, are especially at risk.
Mitigation strategies for CVE-2022-2521 should focus on immediate patching of affected libtiff versions, as the vulnerability has been addressed in subsequent releases. Organizations should implement input validation measures to prevent processing of malformed TIFF files, particularly in scenarios where untrusted input is expected. The recommended approach includes upgrading to libtiff version 4.4.0 or later, which contains the necessary fixes for this memory management issue. Additionally, implementing proper memory sanitization techniques, such as using tools like valgrind or address sanitizers during development and testing phases, can help identify similar issues before deployment. Network segmentation and input filtering should be employed to limit the impact of potential exploitation attempts, while monitoring systems should be configured to detect unusual crash patterns or service disruptions that may indicate exploitation attempts. Security teams should also consider implementing automated patch management processes to ensure timely deployment of security updates across all affected systems and applications that depend on the libtiff library.