CVE-2016-3631 in LibTIFF
Summary
by MITRE
The (1) cpStrips and (2) cpTiles functions in the thumbnail tool in LibTIFF 4.0.6 and earlier allow remote attackers to cause a denial of service (out-of-bounds read) via vectors related to the bytecounts[] array variable.
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Analysis
by VulDB Data Team • 07/13/2022
The vulnerability identified as CVE-2016-3631 resides within the LibTIFF library version 4.0.6 and earlier, specifically affecting the cpStrips and cpTiles functions within the thumbnail tool component. This flaw represents a critical security issue that enables remote attackers to execute denial of service attacks through out-of-bounds read operations. The vulnerability manifests when processing TIFF image files, particularly in scenarios where the bytecounts[] array variable is improperly handled during thumbnail generation processes.
The technical root cause of this vulnerability stems from insufficient bounds checking within the cpStrips and cpTiles functions. When these functions process image data, they fail to validate the size and contents of the bytecounts[] array before accessing its elements. This inadequate validation creates a scenario where maliciously crafted TIFF files can trigger memory access violations, leading to out-of-bounds read conditions that can cause application crashes or system instability. The flaw operates at the intersection of improper input validation and memory management, creating a pathway for attackers to exploit the library's handling of image metadata.
From an operational perspective, this vulnerability presents significant risks to systems that process TIFF image files from untrusted sources. The denial of service impact can affect web applications, image processing servers, and any software that relies on LibTIFF for handling raster image data. Attackers can craft specially formatted TIFF files that, when processed by vulnerable applications, will trigger the out-of-bounds read conditions, potentially causing service interruptions, system crashes, or resource exhaustion. The remote nature of the attack means that systems processing images from the internet or untrusted networks are particularly vulnerable, as the malicious input can be delivered through normal image processing workflows.
The vulnerability aligns with CWE-129, which addresses improper validation of array index values, and can be categorized under ATT&CK technique T1499.004 for endpoint denial of service. Organizations utilizing LibTIFF in their image processing pipelines should prioritize immediate patching to address this vulnerability. The recommended mitigation strategy involves upgrading to LibTIFF version 4.0.7 or later, where the bounds checking mechanisms have been enhanced to properly validate array access operations. Additionally, implementing input validation measures and restricting image file processing from untrusted sources can serve as temporary protective measures until full patch deployment is achieved. Security monitoring should include detection of unusual memory access patterns and application crashes that may indicate exploitation attempts against this vulnerability.