CVE-2016-4065 in Foxit
Summary
by MITRE
The ConvertToPDF plugin in Foxit Reader and PhantomPDF before 7.3.4 on Windows, when the gflags app is enabled, allows remote attackers to cause a denial of service (out-of-bounds read and application crash) via a crafted (1) JPEG, (2) GIF, or (3) BMP image.
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Analysis
by VulDB Data Team • 10/23/2018
The vulnerability identified as CVE-2016-4065 represents a critical security flaw in Foxit Reader and PhantomPDF software versions prior to 7.3.4 on Windows platforms. This issue specifically affects the ConvertToPDF plugin, which is designed to convert various image formats into PDF documents. The vulnerability becomes exploitable when the gflags application debugging tool is enabled, creating a dangerous condition that allows remote attackers to manipulate the software's behavior through carefully crafted image files.
The technical implementation of this vulnerability stems from inadequate input validation within the image parsing routines of the ConvertToPDF plugin. When processing JPEG, GIF, or BMP image files, the software fails to properly validate the structure and boundaries of these image formats, leading to out-of-bounds memory reads. This flaw manifests when maliciously constructed image files are processed, causing the application to attempt reading memory locations beyond the allocated buffer space. The resulting memory access violation triggers an application crash, effectively creating a denial of service condition that can be remotely exploited by attackers.
From an operational impact perspective, this vulnerability poses significant risks to organizations relying on Foxit Reader and PhantomPDF for document processing. The out-of-bounds read condition can be leveraged to cause arbitrary application crashes, disrupting workflow processes and potentially allowing attackers to gain unauthorized access to system resources. The vulnerability's remote exploitability means that attackers can trigger the denial of service condition without requiring physical access to the target system, making it particularly dangerous in enterprise environments where these applications are widely deployed. This flaw directly maps to CWE-125, which describes out-of-bounds read vulnerabilities, and can be classified under ATT&CK technique T1499.004 for denial of service attacks.
The exploitation of this vulnerability requires minimal technical expertise, as attackers only need to prepare specially crafted image files to trigger the memory access violation. This makes the attack surface particularly broad and increases the likelihood of successful exploitation. Organizations using affected versions of Foxit Reader and PhantomPDF should immediately implement mitigations including disabling the gflags debugging tool, updating to version 7.3.4 or later, and implementing network segmentation to limit exposure to potentially malicious image files. Additionally, security monitoring should be enhanced to detect unusual application crash patterns that may indicate exploitation attempts. The vulnerability underscores the critical importance of proper input validation and memory safety practices in document processing applications, particularly those handling user-supplied content through plugins and external conversion tools.