CVE-2018-17664 in Foxit
Summary
by MITRE
This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Foxit Reader 9.2.0.9297. 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 handling of the isCompatibleNS method of a XFA object. The issue results from the lack of validating the existence of an object prior to performing operations on the object. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-6518.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 05/05/2020
CVE-2018-17664 represents a critical remote code execution vulnerability affecting Foxit Reader version 9.2.0.9297, classified under CWE-476 as "Null Pointer Dereference" within the XFA object handling mechanism. This vulnerability manifests when the isCompatibleNS method processes XFA objects without proper validation of object existence before executing operations, creating a dangerous condition where a null pointer dereference can occur. The flaw specifically resides in the document processing pipeline where Foxit Reader fails to verify that XFA objects contain valid references before attempting to access their properties or methods. Attackers can exploit this by crafting malicious PDF documents containing specially constructed XFA objects that trigger the vulnerable code path when the reader attempts to process them.
The operational impact of this vulnerability extends beyond simple code execution to encompass complete system compromise, as the attacker can leverage the vulnerability to run arbitrary code within the context of the Foxit Reader process. This presents a significant risk to enterprise environments where users may inadvertently open malicious documents, particularly in phishing campaigns or supply chain attacks targeting document readers. The requirement for user interaction through visiting malicious web pages or opening malicious files aligns with ATT&CK technique T1203, "Exploitation for Client Execution," which emphasizes the importance of user engagement in successful exploitation. The vulnerability's exploitation path follows a typical attack chain where initial access is gained through social engineering, followed by code execution within the application context, potentially allowing for privilege escalation or lateral movement within the compromised system.
Security professionals should recognize this vulnerability as part of the broader category of memory corruption flaws that affect document processing applications, with implications for both endpoint protection and web application security. The vulnerability demonstrates the critical importance of input validation and proper object reference checking in document parsers, particularly when handling complex structured data formats like XFA (XML Forms Architecture) which can contain nested objects and method calls. Organizations should implement immediate mitigations including disabling automatic PDF processing, deploying web application firewalls to filter malicious content, and ensuring all users have updated to patched versions of Foxit Reader. The vulnerability also highlights the need for comprehensive security testing of document processing libraries and the importance of following secure coding practices that prevent null pointer dereferences through proper validation of object references before access operations. This particular flaw underscores the risks associated with complex document formats that require extensive parsing and object manipulation, where insufficient validation can lead to complete system compromise through remote code execution.