CVE-2016-3625 in LibTIFF
Summary
by MITRE
tif_read.c in the tiff2bw tool in LibTIFF 4.0.6 and earlier allows remote attackers to cause a denial of service (out-of-bounds read) via a crafted TIFF image.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 04/30/2019
The vulnerability identified as CVE-2016-3625 represents a critical out-of-bounds read flaw within the LibTIFF library's tiff2bw tool component. This issue affects versions 4.0.6 and earlier, where the tif_read.c file fails to properly validate input data when processing TIFF image files. The vulnerability stems from insufficient boundary checking during the parsing of TIFF metadata structures, specifically within the bit-width conversion functionality that transforms color TIFF images to bilevel black and white format. Attackers can exploit this weakness by crafting malicious TIFF files that contain malformed or oversized data structures, triggering memory access violations when the tool attempts to read beyond allocated buffer boundaries. The flaw manifests during the image processing workflow where the tiff2bw utility reads and interprets TIFF header information, particularly when handling compression parameters and image dimension specifications. This type of vulnerability falls under the CWE-129 weakness category, which specifically addresses insufficient validation of length of input buffers, and represents a classic example of improper input validation that can lead to memory corruption. The attack vector is remote and requires no authentication, making it particularly dangerous as it can be exploited through automated scanning or by simply opening a malicious file in applications that utilize the affected LibTIFF library.
The operational impact of CVE-2016-3625 extends beyond simple denial of service, as it can potentially enable more sophisticated attacks depending on the execution environment. When the out-of-bounds read occurs, the application typically crashes or becomes unresponsive, resulting in service disruption for any system or application that relies on LibTIFF for image processing tasks. The vulnerability affects a wide range of software systems including graphic design applications, document management systems, web servers processing image uploads, and digital asset management platforms. In enterprise environments, this flaw could be leveraged to disrupt critical document workflows, cause application downtime, or potentially serve as a stepping stone for more advanced attacks if the affected systems are not properly isolated. The flaw's exploitation requires minimal technical skill, making it attractive to threat actors seeking to cause disruption or establish persistent access. From an attacker's perspective, this vulnerability aligns with ATT&CK technique T1059.007 for execution through command-line interfaces and T1499.004 for network denial of service attacks, as it can be used to create persistent disruption of image processing services.
Mitigation strategies for CVE-2016-3625 primarily involve immediate patching of affected systems, as the vulnerability is fully addressed through updates to LibTIFF version 4.0.7 and later releases. Organizations should prioritize patch management processes to ensure all systems utilizing LibTIFF libraries receive the necessary updates, particularly those handling untrusted image files from external sources. Input validation measures should be implemented at application layers that utilize LibTIFF, including additional file format verification and size limiting before passing files to the vulnerable components. Network segmentation and access controls can help limit exposure by restricting direct access to systems processing TIFF files, while application sandboxing provides additional protection against potential exploitation. Security monitoring should include detection of abnormal process behavior or memory access patterns that might indicate exploitation attempts, and regular vulnerability scanning should be conducted to identify other potentially affected components within the software ecosystem. System administrators should also implement file integrity monitoring to detect unauthorized modifications to critical library files and maintain up-to-date threat intelligence to understand evolving attack patterns targeting similar vulnerabilities in image processing libraries. The fix implemented in LibTIFF 4.0.7 includes enhanced buffer boundary checking and improved validation of TIFF metadata structures, specifically addressing the improper input handling that led to the out-of-bounds read condition.