CVE-2017-9117 in LibTIFF
Summary
by MITRE
In LibTIFF 4.0.7, the program processes BMP images without verifying that biWidth and biHeight in the bitmap-information header match the actual input, leading to a heap-based buffer over-read in bmp2tiff.
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Analysis
by VulDB Data Team • 01/08/2025
The vulnerability identified as CVE-2017-9117 represents a critical heap-based buffer over-read flaw within the LibTIFF library version 4.0.7 specifically affecting the bmp2tiff utility. This issue stems from insufficient validation of bitmap information header parameters during the processing of.bmp image files. The vulnerability occurs when the program fails to verify that the biWidth and biHeight fields in the bitmap-information header correspond accurately with the actual dimensions of the input data, creating a scenario where memory access exceeds allocated boundaries.
The technical implementation of this vulnerability involves the bmp2tiff utility's handling of bitmap image headers where it accepts potentially malformed biWidth and biHeight values without proper cross-validation against the actual image data structure. When processing a maliciously crafted bmp file, the program calculates buffer sizes based on these potentially incorrect header values, leading to memory access beyond the allocated heap space. This over-read condition can result in information disclosure, application crashes, or potentially more severe consequences depending on the memory layout and execution context.
From an operational perspective, this vulnerability presents significant risks to systems that process untrusted bitmap images through the bmp2tiff utility or applications built upon LibTIFF 4.0.7. The impact extends beyond simple crashes to potential information leakage where adjacent memory regions may be accessed and potentially exposed. Attackers could exploit this vulnerability by crafting specially formatted bmp files that cause the application to read beyond intended buffer boundaries, potentially accessing sensitive data from memory segments adjacent to the allocated heap buffers. This flaw aligns with CWE-125, which describes out-of-bounds read vulnerabilities, and represents a classic example of improper input validation leading to memory safety issues.
The exploitation of this vulnerability typically requires an attacker to convince a target system to process a maliciously crafted bmp image file through the bmp2tiff utility or an application that utilizes the vulnerable LibTIFF library. The attack vector commonly involves social engineering or automated processing of untrusted image files in environments where image conversion or processing is performed. Systems running vulnerable versions of LibTIFF and processing untrusted image data are particularly at risk, with potential for information disclosure or denial of service attacks. Mitigation strategies include immediate patching of LibTIFF to versions containing the fix, implementing input validation controls, and employing sandboxing or restricted execution environments for image processing utilities.
Security practitioners should note that this vulnerability demonstrates the importance of proper boundary checking and input validation in image processing libraries, particularly when handling format-specific headers that define memory allocation requirements. The issue highlights the need for comprehensive testing of image format parsers against malformed inputs and the implementation of defensive programming practices to prevent heap-based memory corruption. Organizations should prioritize updating their LibTIFF installations and consider implementing additional input sanitization measures for any image processing workflows that might encounter untrusted image files. The vulnerability also underscores the relevance of ATT&CK technique T1203, which covers data exploitation through buffer overflows, and emphasizes the necessity of robust memory safety practices in multimedia processing applications.