CVE-2018-17685 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 PDF files. 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 vulnerability to execute code in the context of the current process. Was ZDI-CAN-6819.
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Analysis
by VulDB Data Team • 07/31/2024
This vulnerability in Foxit Reader 9.2.0.9297 represents a critical remote code execution flaw that demonstrates the dangers of insufficient input validation in PDF processing software. The vulnerability stems from improper handling of user-supplied data within the PDF file parser, creating a type confusion condition that can be exploited by remote attackers. The attack requires user interaction through visiting a malicious webpage or opening a specially crafted PDF file, making it particularly dangerous in phishing campaigns or drive-by download scenarios. This weakness allows an attacker to execute arbitrary code with the privileges of the current process, potentially leading to complete system compromise. The vulnerability is classified under CWE-415 as an improper handling of type confusion, which occurs when the application fails to properly validate data types during processing. From an operational perspective, this flaw affects a widely used PDF reader application, making it a prime target for cybercriminals seeking to exploit the large user base of Foxit Reader. The attack vector through web-based delivery aligns with common tactics described in the MITRE ATT&CK framework under T1203 (Exploitation for Client Execution) and T1059 (Command and Scripting Interpreter) techniques. The vulnerability's impact extends beyond simple code execution to potentially enable privilege escalation and persistence mechanisms within the target system.
The technical implementation of this type confusion vulnerability occurs during the parsing of PDF objects where the application fails to properly validate the data types of elements within the document structure. When processing maliciously crafted PDF files, the parser encounters unexpected data types that cause the application to misinterpret memory layout and execute unintended code sequences. This particular flaw in Foxit Reader's PDF engine demonstrates how complex parsing logic can introduce security gaps when proper input validation is absent. The vulnerability's exploitation requires careful crafting of PDF content that triggers the type confusion, typically involving malformed object definitions or unexpected data structures within the PDF file. Attackers can leverage this condition to overwrite memory locations, redirect execution flow, or inject malicious payloads directly into the running process. The lack of proper bounds checking and type verification in the PDF parsing routine creates multiple potential attack surfaces. Security researchers have identified this as a classic example of how insufficient input sanitization can lead to severe remote code execution vulnerabilities. The vulnerability affects not just the immediate application but can potentially compromise the entire operating system through privilege escalation techniques.
Organizations using Foxit Reader 9.2.0.9297 should implement immediate mitigation strategies to protect their systems from exploitation attempts. The most effective immediate solution involves applying the vendor-provided security patches and updates as soon as they become available. System administrators should also consider implementing network-based protections such as web application firewalls and content filtering solutions that can detect and block malicious PDF content. Email security solutions should be configured to scan PDF attachments for known malicious patterns and suspicious file structures. Network segmentation and access controls can limit the potential impact if an attacker successfully exploits this vulnerability. Monitoring for unusual process execution patterns or unexpected network connections can help detect exploitation attempts. Security teams should also consider disabling PDF processing in web browsers where possible, or implementing sandboxed environments for PDF viewing. The vulnerability's classification under CWE-415 emphasizes the importance of proper type validation and memory management practices in software development. Organizations should conduct comprehensive vulnerability assessments to identify other potentially affected applications that may share similar parsing logic or security flaws. Incident response plans should include specific procedures for handling PDF-based attack vectors, including forensic analysis capabilities to understand exploitation techniques and prevent future incidents. Regular security awareness training for users can help reduce the risk of successful exploitation through social engineering attacks that rely on user interaction with malicious PDF files.