CVE-2017-14837 in Foxit
Summary
by MITRE
This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Foxit Reader 8.3.1.21155. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the pageSpan method of XFA Layout objects. The issue results from the lack of proper validation of user-supplied data, which can result in a type confusion condition. An attacker can leverage this to execute code in the context of the current process. Was ZDI-CAN-5029.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 12/16/2019
CVE-2017-14837 represents a critical type confusion vulnerability affecting Foxit Reader version 8.3.1.21155 that enables remote code execution through malicious web pages or documents. This vulnerability resides within the pageSpan method of XFA Layout objects, demonstrating a fundamental flaw in input validation mechanisms. The vulnerability stems from improper handling of user-supplied data during XFA (XML Forms Architecture) processing, creating conditions where different data types are incorrectly interpreted as the same type, leading to unpredictable behavior and potential code execution.
The technical exploitation of this vulnerability follows a type confusion pattern that aligns with CWE-121 and CWE-122 categories, where memory management errors occur due to insufficient validation of input parameters. When Foxit Reader processes malicious XFA content, the pageSpan method fails to properly validate the data types of parameters passed to it, allowing an attacker to manipulate memory layout and potentially overwrite critical function pointers or execute arbitrary code within the application's process context. This type confusion scenario typically occurs when the application assumes one data type while receiving another, creating opportunities for attackers to craft payloads that exploit these assumptions.
From an operational perspective, this vulnerability requires user interaction to be exploited, making it a client-side attack vector that typically involves social engineering techniques such as phishing emails containing malicious PDF attachments or drive-by downloads from compromised websites. The attack surface is significant given Foxit Reader's widespread adoption in enterprise environments, where users frequently open PDF documents from various sources. The vulnerability's impact extends beyond individual user systems to potentially compromise entire corporate networks, especially when users access untrusted web content or open documents from unknown sources.
The exploitation of this vulnerability demonstrates characteristics consistent with ATT&CK technique T1203 - Exploitation for Client Execution, where adversaries leverage application vulnerabilities to execute malicious code on targeted systems. Organizations should implement multiple layers of defense including regular patch management, web application firewalls, email filtering solutions, and user awareness training to mitigate the risk of exploitation. Security teams should also consider network segmentation and monitoring for suspicious PDF-related activities to detect potential exploitation attempts. Given the nature of the vulnerability, immediate patching is essential as the window for exploitation remains open until the software is updated to address the underlying type confusion issue in the XFA processing engine.
Organizations should prioritize vulnerability assessment and remediation efforts focusing on Foxit Reader installations, particularly those running version 8.3.1.21155 or earlier, as this vulnerability represents a significant risk to information security. The vulnerability's classification as a remote code execution flaw necessitates immediate attention from security operations teams to evaluate affected systems and implement appropriate mitigations while planning for comprehensive patch deployment across all endpoints.