CVE-2021-31473 in Foxit
Summary
by MITRE • 05/21/2021
This vulnerability allows remote attackers to execute arbitrary code on affected installations of Foxit Reader 10.1.3.37598. 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 browseForDoc function. The issue results from the lack of proper validation of user-supplied data, which can result in a write past the end of an allocated data structure. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-13523.
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Analysis
by VulDB Data Team • 05/04/2026
CVE-2021-31473 represents a critical buffer overflow vulnerability affecting Foxit Reader version 10.1.3.37598 that enables remote code execution through crafted malicious content. This vulnerability resides within the browseForDoc function, which processes user-supplied data without adequate validation mechanisms. The flaw constitutes a classic buffer overflow condition where insufficient bounds checking allows an attacker to write data beyond the allocated memory boundaries of a data structure. The vulnerability requires user interaction to be exploited, meaning victims must either visit a malicious webpage or open a specially crafted file containing the malicious payload. This attack vector aligns with common social engineering tactics where users are lured into interacting with compromised content, making the exploitation particularly dangerous in enterprise environments where users frequently encounter untrusted documents. The technical implementation of this vulnerability demonstrates a failure in input sanitization practices, where the browseForDoc function fails to validate the length and content of user-provided parameters before processing them. This oversight creates an opportunity for attackers to craft malicious input that overflows adjacent memory regions, potentially corrupting program execution flow and enabling arbitrary code execution within the context of the currently running Foxit Reader process. The security implications extend beyond simple code execution as this vulnerability can be leveraged to escalate privileges or gain unauthorized access to sensitive system resources, particularly when Foxit Reader runs with elevated permissions. From a cybersecurity perspective, this vulnerability maps directly to CWE-121, which describes heap-based buffer overflow conditions, and aligns with ATT&CK technique T1059.007 for command and scripting interpreter execution. The vulnerability's exploitation capability makes it particularly attractive to threat actors targeting enterprise networks where Foxit Reader is commonly deployed for document viewing and editing operations. Organizations should consider implementing network-based protections such as web application firewalls and content filtering systems to prevent access to known malicious domains and files, while also ensuring timely patch deployment to address this specific buffer overflow condition. The vulnerability highlights the critical importance of proper input validation and memory management practices in software development, particularly for applications that process untrusted user data. Regular security assessments and penetration testing should include evaluation of similar buffer overflow conditions in document processing applications, as these represent persistent attack vectors in enterprise security landscapes. The remediation approach must involve immediate patching of the affected Foxit Reader version, alongside comprehensive security awareness training to reduce the risk of successful social engineering attacks that leverage this vulnerability.