CVE-2016-3632 in LibTIFF
Summary
by MITRE
The _TIFFVGetField function in tif_dirinfo.c in LibTIFF 4.0.6 and earlier allows remote attackers to cause a denial of service (out-of-bounds write) or execute arbitrary code via a crafted TIFF image.
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Analysis
by VulDB Data Team • 09/19/2022
The vulnerability identified as CVE-2016-3632 represents a critical security flaw within the LibTIFF library version 4.0.6 and earlier, specifically within the _TIFFVGetField function located in the tif_dirinfo.c file. This issue manifests as a remote code execution vulnerability that can be exploited through the careful crafting of TIFF image files, making it particularly dangerous for systems that process untrusted image data. The vulnerability stems from improper input validation and memory management within the library's handling of TIFF directory information structures, creating opportunities for attackers to manipulate memory operations through maliciously constructed image files.
The technical exploitation of this vulnerability involves an out-of-bounds write condition that occurs when the _TIFFVGetField function processes certain TIFF directory entries without adequate bounds checking. When a malicious TIFF file is processed, the function attempts to write data beyond the allocated memory boundaries of internal data structures, potentially overwriting adjacent memory regions. This memory corruption can lead to unpredictable behavior including program crashes, denial of service conditions, or more critically, arbitrary code execution. The vulnerability is classified under CWE-121, which describes "Stack-based Buffer Overflow" conditions, though the specific implementation in LibTIFF involves heap-based memory corruption. The flaw demonstrates a classic buffer over-read/write vulnerability where the application fails to validate the size or content of directory entries before processing them.
From an operational perspective, systems utilizing LibTIFF for image processing are at significant risk when handling untrusted TIFF files, as this vulnerability can be exploited remotely through web applications, file upload mechanisms, or any service that processes TIFF image data. The impact extends across numerous applications including web browsers, image processing software, document management systems, and digital asset management platforms that rely on LibTIFF for image handling. Attackers can leverage this vulnerability to execute malicious code with the privileges of the affected application, potentially leading to complete system compromise. The vulnerability affects a wide range of platforms and applications since LibTIFF is widely used across multiple operating systems and software ecosystems, making it a high-priority target for exploitation. Organizations running services that process TIFF files, such as content management systems, image servers, or document processing pipelines, face substantial risk from this vulnerability.
Mitigation strategies for CVE-2016-3632 focus primarily on immediate remediation through library updates to versions 4.0.7 and later, where the vulnerability has been addressed through improved input validation and memory management. System administrators should prioritize patching affected systems and applications that utilize LibTIFF, particularly those handling untrusted image data from external sources. Additional defensive measures include implementing strict input validation for all image files, deploying web application firewalls to filter suspicious file uploads, and utilizing sandboxing techniques to isolate image processing operations. Network segmentation and access controls can limit the potential impact of exploitation by restricting access to vulnerable systems. The ATT&CK framework categorizes this vulnerability under T1059 for command and script interpreter, as exploitation may involve executing malicious code through compromised image processing pipelines. Organizations should also implement monitoring solutions to detect unusual patterns in image processing activities that might indicate exploitation attempts, and conduct regular vulnerability assessments to identify systems running vulnerable versions of LibTIFF.