CVE-2020-35523 in LibTIFF
Summary
by MITRE • 03/10/2021
An integer overflow flaw was found in libtiff that exists in the tif_getimage.c file. This flaw allows an attacker to inject and execute arbitrary code when a user opens a crafted TIFF file. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.
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Analysis
by VulDB Data Team • 11/11/2025
The vulnerability identified as CVE-2020-35523 represents a critical integer overflow flaw within the libtiff library, specifically within the tif_getimage.c source file. This flaw constitutes a software security weakness that can be exploited through maliciously crafted TIFF image files, creating a significant risk to system security and stability. The vulnerability stems from improper input validation and arithmetic handling within the library's image processing routines, where integer overflow conditions can occur during memory allocation calculations.
The technical implementation of this vulnerability involves the manipulation of integer values during TIFF file processing operations, particularly when calculating memory requirements for image data handling. When a user opens a specially crafted TIFF file, the library's processing code fails to properly validate integer inputs, leading to arithmetic overflow conditions that can result in memory corruption. This memory corruption scenario creates opportunities for attackers to manipulate the program execution flow through controlled data injection, potentially enabling arbitrary code execution within the context of the application using libtiff.
From an operational impact perspective, this vulnerability presents a severe threat to system confidentiality, integrity, and availability as outlined in the original description. The potential for remote code execution means that attackers can compromise systems simply by enticing users to open malicious TIFF files, making this vulnerability particularly dangerous in environments where users may encounter untrusted image files. The exploitability of this flaw is heightened by the widespread use of libtiff across numerous applications and operating systems, including web browsers, image viewers, and document processing software.
The vulnerability aligns with CWE-190, which specifically addresses integer overflow and underflow conditions in software implementations. This classification indicates that the flaw involves improper handling of integer arithmetic operations that can result in unexpected behavior when integer values exceed their representable range. The attack surface extends beyond simple local exploitation to include network-based attacks where malicious TIFF files can be delivered through web applications, email attachments, or file sharing systems, making the vulnerability particularly concerning for enterprise security environments.
Security mitigation strategies for CVE-2020-35523 should prioritize immediate patching of affected libtiff versions, with system administrators monitoring for updates from software vendors who utilize this library. Additionally, implementing strict file validation and sandboxing mechanisms for TIFF file processing can help reduce the risk of exploitation. Network-based defenses should include content filtering and restriction of TIFF file types in email systems and web applications. The vulnerability demonstrates the importance of robust input validation and integer arithmetic handling in security-critical libraries, as highlighted by ATT&CK technique T1203, which covers the exploitation of software vulnerabilities for privilege escalation and code execution. Organizations should also consider implementing application whitelisting and monitoring for suspicious file processing activities to detect potential exploitation attempts.