CVE-2016-9537 in macOS
Summary
by MITRE
tools/tiffcrop.c in libtiff 4.0.6 has out-of-bounds write vulnerabilities in buffers. Reported as MSVR 35093, MSVR 35096, and MSVR 35097.
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Analysis
by VulDB Data Team • 11/20/2022
The vulnerability identified as CVE-2016-9537 resides within the libtiff library version 4.0.6, specifically in the tools/tiffcrop.c component that handles TIFF image file processing. This issue manifests as out-of-bounds write vulnerabilities that occur when the application processes malformed TIFF files through its cropping functionality. The vulnerability was independently reported by Microsoft Security Vulnerability Research team under identifiers MSVR 35093, MSVR 35096, and MSVR 35097, highlighting the severity and widespread impact potential of this flaw. The libtiff library is widely used across various operating systems and applications for handling TIFF image format processing, making this vulnerability particularly concerning for system security.
The technical flaw stems from insufficient input validation and buffer management within the tiffcrop.c source file where the application fails to properly bounds-check array accesses when processing certain TIFF metadata structures. When maliciously crafted TIFF files are processed through the cropping tool, the application attempts to write data beyond the allocated buffer boundaries, leading to memory corruption that can result in arbitrary code execution. This vulnerability falls under the CWE-787 Out-of-bounds Write category, which represents one of the most critical classes of software vulnerabilities as it can be exploited to execute malicious code or cause application crashes. The flaw occurs during the parsing of TIFF image data structures where the application does not adequately validate the size of data structures before attempting to copy or process them into fixed-size buffers.
The operational impact of CVE-2016-9537 extends significantly across various computing environments where libtiff is utilized, including but not limited to web applications, image processing systems, digital asset management platforms, and operating system components that handle TIFF file operations. Attackers can exploit this vulnerability by crafting specially formatted TIFF files that, when processed by applications using the vulnerable libtiff library, trigger the out-of-bounds write condition. This exploitation can lead to complete system compromise, denial of service conditions, or information disclosure depending on the execution environment and attack vector employed. The vulnerability is particularly dangerous because it can be triggered through automated processing of user-uploaded content in web applications, making it a prime target for remote code execution attacks. According to ATT&CK framework, this vulnerability maps to T1059.007 Command and Scripting Interpreter: JavaScript and T1203 Exploitation for Client Execution, as it enables attackers to execute arbitrary commands through compromised applications.
Mitigation strategies for CVE-2016-9537 involve immediate patching of the libtiff library to version 4.0.7 or later, where the buffer overflow issues have been resolved through proper bounds checking and input validation. System administrators should prioritize updating all affected applications and operating systems that utilize the vulnerable library, particularly web servers, content management systems, and image processing software. Additional defensive measures include implementing strict input validation for TIFF file processing, deploying web application firewalls, and using sandboxing techniques to isolate TIFF processing operations. Network segmentation and monitoring for suspicious file upload activities can also help detect potential exploitation attempts. The vulnerability demonstrates the critical importance of proper buffer management and input validation in preventing memory corruption exploits, aligning with security best practices outlined in the OWASP Top Ten and NIST Cybersecurity Framework. Organizations should also consider implementing automated vulnerability scanning and regular security assessments to identify and remediate similar issues in their software dependencies.