CVE-2017-5563 in LibTIFF
Summary
by MITRE
LibTIFF version 4.0.7 is vulnerable to a heap-based buffer over-read in tif_lzw.c resulting in DoS or code execution via a crafted bmp image to tools/bmp2tiff.
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Analysis
by VulDB Data Team • 05/14/2026
The vulnerability identified as CVE-2017-5563 represents a critical heap-based buffer over-read condition within the LibTIFF library version 4.0.7 specifically affecting the LZW compression handling module. This flaw exists in the tif_lzw.c file and can be exploited through maliciously crafted bmp image files when processed by the bmp2tiff utility. The vulnerability stems from inadequate input validation and boundary checking during the decompression process of LZW-encoded data within bitmap image formats. The flaw allows attackers to manipulate the decompression algorithm by providing specially constructed input that causes the software to read beyond allocated memory boundaries, potentially leading to system instability or arbitrary code execution.
The technical implementation of this vulnerability occurs when the bmp2tiff utility processes a malformed bmp image file that contains crafted LZW compression data. During the decompression phase, the library fails to properly validate the size parameters of the compressed data stream, allowing an attacker to manipulate the decompression algorithm to access memory locations beyond the intended buffer boundaries. This over-read condition can result in information disclosure, application crashes, or potentially enable remote code execution depending on the specific memory layout and exploitation circumstances. The vulnerability is particularly concerning because it affects a widely used library that handles image format conversions, making it accessible to attackers who can craft malicious image files for processing.
From an operational security perspective, this vulnerability presents significant risks to systems that process user-uploaded or third-party bitmap images through the bmp2tiff utility. The attack surface expands to any application or service that relies on LibTIFF for image format conversion, including web applications, document management systems, and digital asset management platforms. The potential for denial of service attacks is high as the over-read condition can cause application crashes and system instability. Additionally, the possibility of code execution makes this vulnerability particularly dangerous for environments where the bmp2tiff utility is used in automated processing pipelines or when handling untrusted image inputs from external sources.
The vulnerability aligns with CWE-125, which describes "Out-of-bounds Read" conditions, and represents a classic example of improper input validation in memory handling operations. According to ATT&CK framework, this vulnerability could be leveraged through initial access vectors such as malicious file uploads or remote exploitation in web applications. The exploitation chain typically involves crafting a malicious bmp file that triggers the vulnerable decompression path, followed by successful execution of the buffer over-read condition. Organizations should implement immediate mitigations including updating to LibTIFF version 4.0.8 or later, which contains the necessary patches to address the buffer over-read condition. Additionally, input validation measures should be implemented at the application level to restrict file types and validate image headers before processing, while network-based mitigations such as content filtering can help prevent malicious files from reaching vulnerable systems.
The impact of this vulnerability extends beyond immediate exploitation potential to include long-term security implications for organizations relying on LibTIFF for image processing workflows. System administrators should conduct comprehensive vulnerability assessments to identify all systems using affected versions of LibTIFF and implement proper patch management procedures. The vulnerability demonstrates the importance of robust memory safety practices in image processing libraries and highlights the need for thorough input validation in compression algorithms. Organizations should also consider implementing sandboxing techniques for image processing operations and establish monitoring procedures to detect potential exploitation attempts through unusual memory access patterns or application crashes. Regular security audits of third-party libraries and dependencies remain crucial for identifying similar vulnerabilities in other components of the software supply chain.