CVE-2018-17659 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 title property of a Host 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-6511.
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Analysis
by VulDB Data Team • 05/05/2020
CVE-2018-17659 represents a critical remote code execution vulnerability affecting Foxit Reader version 9.2.0.9297, classified under CWE-476 as NULL Pointer Dereference, which falls within the broader category of software security flaws that can be exploited through improper input validation. This vulnerability resides in the PDF viewer's handling of the title property within a Host object, where the application fails to validate whether an object exists before performing operations on it. The flaw constitutes a classic null pointer dereference scenario where the software assumes object existence without proper verification, creating an exploitable condition that allows malicious actors to inject and execute arbitrary code on targeted systems. The vulnerability requires user interaction to be exploited, specifically requiring either visiting a malicious webpage or opening a crafted malicious file, making it a client-side attack vector that leverages social engineering techniques to deliver the payload.
The technical implementation of this vulnerability demonstrates a fundamental flaw in the object-oriented programming practices within Foxit Reader's PDF parsing engine, where the Host object's title property handling does not perform necessary null checks before proceeding with operations. This type of vulnerability typically occurs when developers assume certain objects will always be present in memory or when they fail to implement proper error handling mechanisms for object access. The lack of validation creates a condition where an attacker can craft a malicious PDF document or webpage that manipulates the Host object's title property in such a way that when the application attempts to process it, the software crashes or behaves unpredictably, allowing the attacker to inject malicious code that executes with the privileges of the current process. The vulnerability's classification as a remote code execution issue means that attackers can exploit this flaw from a distance without requiring physical access to the target system, making it particularly dangerous in enterprise environments where users frequently access untrusted web content.
The operational impact of CVE-2018-17659 extends beyond simple code execution, as it provides attackers with a foothold for more sophisticated attacks within compromised systems, potentially enabling privilege escalation, data exfiltration, or further lateral movement within networks. This vulnerability aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter, where adversaries can leverage the code execution capability to run malicious commands or scripts. The exploitability of this vulnerability is enhanced by the fact that it requires minimal user interaction, typically through phishing emails containing malicious attachments or compromised websites that automatically trigger the exploit when opened. Organizations running Foxit Reader 9.2.0.9297 are particularly vulnerable to attacks that could result in full system compromise, as the executed code operates within the context of the current process, potentially allowing attackers to access sensitive documents, credentials, or system resources. The vulnerability's presence in a widely used PDF reader means that successful exploitation can affect numerous users across different industries, including government agencies, financial institutions, and healthcare organizations that rely on document viewing applications for daily operations.
Mitigation strategies for CVE-2018-17659 should prioritize immediate patching of Foxit Reader installations to version 9.2.1.9314 or later, which contains the necessary fixes for the null pointer dereference issue. Organizations should implement network-based protections such as web application firewalls and content filtering solutions that can detect and block malicious PDF files or web pages containing the specific exploit patterns. Additionally, user education and awareness programs should be enhanced to reduce the likelihood of users interacting with malicious content, particularly through email phishing campaigns that leverage this vulnerability. Security teams should monitor network traffic for suspicious PDF file downloads or access patterns that might indicate exploitation attempts, and implement sandboxing solutions for PDF processing to isolate potentially malicious content. The vulnerability serves as a reminder of the importance of proper input validation and object-oriented programming practices, with organizations needing to establish robust code review processes that specifically address null pointer dereference conditions and other memory safety issues. Implementation of principle of least privilege access controls and regular security assessments can further reduce the potential impact of successful exploitation attempts, while maintaining up-to-date threat intelligence feeds can help organizations prepare for similar vulnerabilities that may emerge in other software applications.