CVE-2018-17666 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 exportData method 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-6520.
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Analysis
by VulDB Data Team • 05/05/2020
CVE-2018-17666 represents a critical remote code execution vulnerability affecting Foxit Reader version 9.2.0.9297, demonstrating a classic object validation flaw that aligns with CWE-476 which addresses null pointer dereference conditions. This vulnerability operates through the exportData method of a host object within the PDF rendering engine, where insufficient input validation leads to improper object handling that can be exploited by malicious actors. The flaw specifically occurs when the application fails to verify whether an object exists before attempting operations on it, creating a dangerous condition where arbitrary code execution becomes possible. The vulnerability requires user interaction to be exploited, meaning that targets must either visit a malicious webpage or open a crafted malicious file containing the exploit payload, making it a prime candidate for phishing attacks and drive-by download scenarios.
The technical implementation of this vulnerability stems from improper object lifecycle management within the Foxit Reader application's JavaScript execution environment. When processing PDF files, the application's host object handling mechanism does not properly validate object existence before invoking operations on the exportData method, leading to a scenario where memory corruption can occur. This type of vulnerability falls under the ATT&CK framework's technique T1059.007 for command and scripting interpreter, specifically JavaScript, and represents a path to privilege escalation through application sandbox bypass. The attack vector typically involves embedding malicious JavaScript code within PDF documents that, when processed by the vulnerable reader, triggers the flawed exportData method execution path. The lack of proper validation creates a window where attackers can manipulate memory structures and execute arbitrary code within the context of the Foxit Reader process, potentially leading to full system compromise.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with persistent access to target systems through the PDF reader application. Attackers can leverage this vulnerability to install backdoors, steal sensitive data, or establish persistent command and control channels without requiring elevated privileges. The vulnerability's remote exploitation capability makes it particularly dangerous in enterprise environments where PDF documents are frequently shared and opened by multiple users. Organizations running vulnerable versions of Foxit Reader face significant risk of targeted attacks, especially when users are unaware of the potential dangers associated with opening untrusted PDF files. The vulnerability's classification as a remote code execution flaw places it in the highest severity category, as it enables attackers to gain complete control over affected systems without requiring physical access or prior authentication.
Mitigation strategies for CVE-2018-17666 should focus on immediate patching of Foxit Reader installations to version 9.2.1.9301 or later, which contains the necessary fixes for the object validation flaw. Organizations should implement strict PDF file filtering policies, including content scanning and sandboxing of PDF documents before opening them in production environments. Network-based protections such as web application firewalls and content filtering solutions can help block malicious PDF content from reaching users. Additionally, user education programs should emphasize the importance of avoiding suspicious PDF files and websites, while system administrators should consider implementing browser-based PDF viewing restrictions to prevent automatic execution of potentially malicious content. The vulnerability's characteristics make it particularly suitable for exploitation through social engineering campaigns, so comprehensive security awareness training becomes essential for preventing successful exploitation attempts. Organizations should also consider implementing endpoint detection and response solutions that can identify anomalous behavior patterns associated with exploitation attempts, providing additional layers of defense beyond traditional signature-based detection methods.