CVE-2016-9532 in LibTIFF
Summary
by MITRE
Integer overflow in the writeBufferToSeparateStrips function in tiffcrop.c in LibTIFF before 4.0.7 allows remote attackers to cause a denial of service (out-of-bounds read) via a crafted tif file.
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Analysis
by VulDB Data Team • 10/07/2024
The vulnerability identified as CVE-2016-9532 represents a critical integer overflow flaw within the LibTIFF library's tiffcrop.c component, specifically in the writeBufferToSeparateStrips function. This issue affects versions of LibTIFF prior to 4.0.7 and creates a remote attack vector that can be exploited through maliciously crafted TIFF files. The vulnerability stems from improper handling of integer arithmetic during buffer operations, which can lead to memory corruption and subsequent system instability. The flaw demonstrates a classic example of insufficient input validation and boundary checking in image processing libraries that handle complex file formats. When a malicious TIFF file is processed by an application using the vulnerable LibTIFF version, the integer overflow condition triggers an out-of-bounds read operation that can cause the application to crash or behave unpredictably.
The technical implementation of this vulnerability involves the writeBufferToSeparateStrips function where integer overflow occurs during calculations related to buffer sizing and memory allocation for separate strips within TIFF image files. This function processes image data by writing buffers to separate strips, but fails to properly validate or constrain integer values during arithmetic operations. The overflow condition typically manifests when the library attempts to calculate buffer sizes or strip dimensions based on maliciously crafted metadata within the TIFF file header. When integer overflow occurs, it results in a buffer that is significantly smaller than expected, leading to out-of-bounds memory access patterns. This type of vulnerability falls under CWE-190, which specifically addresses integer overflow and underflow conditions, and represents a direct threat to software robustness and memory safety. The vulnerability operates at the intersection of file format parsing and memory management, making it particularly dangerous in applications that process untrusted image data.
The operational impact of CVE-2016-9532 extends beyond simple denial of service to potentially enable more sophisticated attack vectors depending on the application context. Remote attackers can leverage this vulnerability to cause service disruption across any system that utilizes the vulnerable LibTIFF library for TIFF file processing, including web applications, image servers, and document management systems. The out-of-bounds read condition can result in application crashes, data corruption, or potentially even arbitrary code execution in scenarios where the memory corruption leads to exploitable conditions. This vulnerability affects the broader ATT&CK framework's execution and privilege escalation categories, as it can be used to disrupt services and potentially gain unauthorized access to systems. The vulnerability's remote nature means that attackers do not require local access to exploit it, making it particularly dangerous in web-facing applications where TIFF files are processed without proper sanitization.
Mitigation strategies for CVE-2016-9532 primarily focus on immediate library updates and implementation of robust input validation measures. Organizations should prioritize upgrading to LibTIFF version 4.0.7 or later, which contains the necessary patches to address the integer overflow condition in the writeBufferToSeparateStrips function. Additionally, implementing proper input sanitization and validation for all TIFF file processing operations can provide defense-in-depth measures. Security teams should consider deploying network-based intrusion detection systems that can identify and block malicious TIFF files attempting to exploit this vulnerability. Application developers should also implement proper error handling and memory protection mechanisms when processing image files, including bounds checking and memory allocation validation. The vulnerability highlights the importance of regular security updates and the need for comprehensive testing of third-party libraries in security-critical applications, particularly those handling untrusted file formats. Organizations should also consider implementing sandboxing mechanisms for image processing operations to limit the potential impact of similar vulnerabilities in the future.