CVE-2016-3622 in LibTIFF
Summary
by MITRE
The fpAcc function in tif_predict.c in the tiff2rgba tool in LibTIFF 4.0.6 and earlier allows remote attackers to cause a denial of service (divide-by-zero error) via a crafted TIFF image.
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Analysis
by VulDB Data Team • 07/13/2022
The vulnerability identified as CVE-2016-3622 represents a critical denial of service flaw within the LibTIFF library version 4.0.6 and earlier. This issue specifically affects the tif_predict.c component and the tiff2rgba tool which processes TIFF image files. The vulnerability manifests through the fpAcc function where a divide-by-zero error occurs when processing malformed TIFF images, creating a condition that can be exploited remotely by attackers to disrupt system operations. The flaw exists in the prediction decoding process that handles compressed TIFF images, particularly those using predictor schemes that involve floating-point arithmetic operations. This vulnerability falls under the category of improper error handling and input validation, as the software fails to properly validate the structure of incoming TIFF data before attempting mathematical operations. The impact extends beyond simple service disruption since it can be leveraged in automated attack scenarios where adversaries might flood systems with malicious TIFF files, causing cascading failures across multiple applications that depend on LibTIFF for image processing. The vulnerability is classified as CWE-369, which specifically addresses the divide-by-zero error condition, and aligns with ATT&CK technique T1499.004 for network denial of service attacks. The flaw demonstrates a lack of proper input sanitization and robust error handling mechanisms within the image processing pipeline, where the software assumes valid predictor values without proper validation checks. This weakness is particularly dangerous in environments where TIFF files are processed automatically, such as web applications, document management systems, or image processing servers that accept user uploads. The vulnerability can be exploited by crafting a TIFF image with malformed predictor data that forces the fpAcc function to perform division operations with zero as the denominator, resulting in immediate program termination or system instability. The exploitability of this vulnerability is high due to the widespread use of LibTIFF across numerous applications and operating systems, making it a prime target for denial of service attacks. Security researchers have identified that the issue stems from insufficient validation of predictor parameters during the decompression phase, where the software does not adequately check for zero values before executing mathematical operations. The affected software components include not only the tiff2rgba utility but also any application that incorporates LibTIFF's prediction decoding functionality, potentially affecting a broad range of image processing applications. The vulnerability can be mitigated through immediate patching of LibTIFF to version 4.0.7 or later, which includes proper input validation and error handling for predictor values. Additionally, system administrators should implement input validation measures at network boundaries and application levels to filter out potentially malicious TIFF files. The remediation process requires updating the LibTIFF library across all affected systems, including web servers, image processing applications, and any software that relies on TIFF format handling. Organizations should also consider implementing sandboxing techniques for TIFF file processing and establishing monitoring protocols to detect unusual patterns of service disruption that might indicate exploitation attempts. The vulnerability highlights the importance of robust input validation in multimedia processing libraries and demonstrates how seemingly minor flaws in mathematical operations can lead to significant system stability issues.