CVE-2017-7600 in LibTIFF
Summary
by MITRE
LibTIFF 4.0.7 has an "outside the range of representable values of type unsigned char" undefined behavior issue, which might allow remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact via a crafted image.
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Analysis
by VulDB Data Team • 11/28/2022
The vulnerability identified as CVE-2017-7600 affects LibTIFF version 4.0.7 and represents a critical undefined behavior flaw that stems from improper handling of image data during the parsing process. This issue manifests when the library encounters image files containing data that falls outside the valid range of values that can be represented by an unsigned char data type, creating a scenario where the program's behavior becomes unpredictable and potentially exploitable. The vulnerability resides in the TIFF image parsing functionality where the library fails to properly validate input data before processing it, leading to potential memory corruption or application instability. This type of vulnerability is particularly dangerous because it can be triggered through crafted image files that appear legitimate but contain maliciously constructed data elements designed to exploit the undefined behavior.
The technical root cause of this vulnerability lies in the improper bounds checking and data validation mechanisms within the LibTIFF library implementation. When processing TIFF image files, the library attempts to convert certain data values into unsigned char variables without adequate validation of whether these values fall within the representable range of 0-255 for unsigned char data types. This undefined behavior can occur during various stages of image processing including color space conversion, compression handling, or metadata parsing. The vulnerability is classified under CWE-129 as "Improper Validation of Array Index" and also relates to CWE-704 as "Incorrect Type Conversion or Cast," demonstrating how inadequate input validation can lead to serious security implications. The flaw allows attackers to craft malicious image files that, when processed by vulnerable applications using LibTIFF, can cause the application to crash or exhibit unpredictable behavior.
The operational impact of CVE-2017-7600 extends beyond simple denial of service to potentially enable more sophisticated attacks depending on the application context. Remote attackers can exploit this vulnerability by delivering specially crafted TIFF images to applications that utilize LibTIFF for image processing, resulting in application crashes that can be leveraged for denial of service attacks against web services, file processing systems, or any application that handles TIFF image files. The vulnerability's potential for unspecified other impacts suggests that under certain conditions, attackers might be able to achieve more severe consequences including arbitrary code execution or information disclosure, particularly when the vulnerable applications are running with elevated privileges or in environments where memory corruption could be exploited further. This vulnerability affects a wide range of software systems including web browsers, image processing applications, document management systems, and content management platforms that rely on LibTIFF for TIFF file handling.
Mitigation strategies for CVE-2017-7600 should prioritize immediate patching of affected LibTIFF versions to 4.0.8 or later, which contains the necessary fixes for the undefined behavior issue. Organizations should implement comprehensive input validation measures for all image file processing workflows, including mandatory file format checking and size validation before processing. Network-based mitigations can include implementing content filtering systems that scan image uploads for suspicious patterns or employing sandboxing techniques that isolate image processing operations from core application functionality. From an operational perspective, security teams should conduct thorough vulnerability assessments of all systems that utilize LibTIFF libraries and establish monitoring protocols to detect potential exploitation attempts. The ATT&CK framework categorizes this vulnerability under T1203 as "Exploitation for Client Execution" and T1499 as "Endpoint Denial of Service," highlighting the need for both preventive measures and detection capabilities. Regular security updates and dependency management practices should be enforced to prevent similar vulnerabilities from accumulating in software environments, as this type of undefined behavior issue often indicates broader architectural weaknesses in input validation and memory handling processes.