CVE-2020-35522 in LibTIFF
Summary
by MITRE • 03/10/2021
In LibTIFF, there is a memory malloc failure in tif_pixarlog.c. A crafted TIFF document can lead to an abort, resulting in a remote denial of service attack.
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Analysis
by VulDB Data Team • 11/11/2025
The vulnerability identified as CVE-2020-35522 represents a critical memory allocation failure within the LibTIFF library's PixarLog compression handling component. This flaw exists in the tif_pixarlog.c source file where improper memory management during the processing of specially crafted TIFF image files can cause the application to terminate unexpectedly. The issue stems from inadequate error handling when allocating memory for decompressing PixarLog compressed image data, creating a condition where malicious input can trigger a malloc failure that results in program abortion.
The technical exploitation of this vulnerability occurs when a malicious TIFF file containing crafted PixarLog compression data is processed by any application relying on LibTIFF for image handling. The flaw manifests as a failure in the memory allocation routine that occurs during the decompression phase of the PixarLog compression algorithm. When the library attempts to allocate memory for processing the malformed input data, the malloc function fails to return sufficient memory, causing the application to abort rather than gracefully handle the error condition. This behavior creates a predictable crash scenario that can be reliably reproduced through specific input patterns.
From an operational impact perspective, this vulnerability presents a significant remote denial of service threat to any system that processes TIFF images using LibTIFF. Applications such as image viewers, document management systems, web servers handling image uploads, and content management platforms become vulnerable to this attack vector. The remote nature of the exploit means that an attacker can trigger the vulnerability from any location without requiring local access to the target system. The service disruption is immediate and complete, as the application crashes and becomes unavailable until manually restarted, potentially leading to extended downtime for affected services.
The vulnerability aligns with CWE-704, which addresses improper handling of memory allocation failures, and demonstrates characteristics consistent with ATT&CK technique T1499.004 for network denial of service attacks. Organizations using LibTIFF in production environments face substantial risk of service interruption, particularly those handling untrusted image input from external sources. The exploit requires minimal sophistication to execute, making it particularly dangerous for high-availability systems where uptime is critical. The impact extends beyond simple service disruption to include potential business continuity issues and user experience degradation.
Mitigation strategies should focus on immediate patch application for LibTIFF versions containing the fix, as well as implementing input validation measures that can detect and reject malformed TIFF files before they reach the decompression stage. Organizations should consider deploying additional security layers such as sandboxed image processing environments and implementing rate limiting for image upload operations. Network-level protections including intrusion detection systems and firewall rules that can identify suspicious image file patterns may provide additional defense in depth. Regular security auditing of image processing pipelines and maintaining up-to-date library versions remain essential practices for preventing exploitation of similar memory handling vulnerabilities in the future.