CVE-2015-8683 in LibTIFF
Summary
by MITRE
The putcontig8bitCIELab function in tif_getimage.c in LibTIFF 4.0.6 allows remote attackers to cause a denial of service (out-of-bounds read) via a packed TIFF image.
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Analysis
by VulDB Data Team • 07/24/2022
The vulnerability identified as CVE-2015-8683 resides within the LibTIFF library version 4.0.6, specifically within the putcontig8bitCIELab function located in the tif_getimage.c source file. This flaw represents a critical out-of-bounds read condition that can be exploited by remote attackers to trigger a denial of service scenario. The vulnerability manifests when processing packed TIFF images, which are commonly used in scientific and medical imaging applications where color space conversion is required. The function processes continuous 8-bit CIELab color data and appears to lack proper bounds checking mechanisms when handling image data structures.
The technical implementation of this vulnerability stems from insufficient input validation within the image processing pipeline. When a specially crafted packed TIFF image is processed, the putcontig8bitCIELab function attempts to read memory locations beyond the allocated buffer boundaries. This occurs because the function does not adequately verify the dimensions or data structure integrity of the incoming TIFF image before performing memory operations. The flaw is categorized under CWE-129 as an insufficient input validation issue, where the application fails to properly validate array indices or buffer limits. This type of vulnerability falls squarely within the ATT&CK technique T1499.004 for network denial of service, as it can be leveraged to disrupt services through memory corruption.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the stability of applications that depend on LibTIFF for image processing. Systems utilizing this library for handling TIFF images in medical imaging, satellite imagery processing, or scientific visualization may experience crashes or unresponsive behavior when encountering maliciously crafted files. The remote attack vector means that adversaries can exploit this vulnerability without requiring local access, making it particularly dangerous in web-facing applications or file processing services. The out-of-bounds read can result in application crashes, memory corruption, or potentially provide a pathway for more sophisticated attacks if combined with other vulnerabilities in the processing pipeline.
Mitigation strategies for CVE-2015-8683 should prioritize immediate patching of affected LibTIFF versions to 4.0.7 or later, which contains the necessary fixes for the bounds checking issue. Organizations should implement robust input validation procedures for all TIFF file processing, including pre-validation of image headers and structure integrity checks. Network segmentation and file type filtering can help reduce exposure by limiting access to potentially malicious TIFF files. Additionally, monitoring systems should be configured to detect unusual application behavior or crash patterns that may indicate exploitation attempts. The fix implemented by the LibTIFF maintainers involved adding proper boundary checks within the putcontig8bitCIELab function to ensure that memory reads remain within allocated buffer limits. Security teams should also consider implementing sandboxing techniques for image processing operations to contain potential impacts from exploitation attempts.