CVE-2018-17653 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 resolveNode method of a TimeField. 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-6503.
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Analysis
by VulDB Data Team • 05/05/2020
CVE-2018-17653 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. This vulnerability resides within the TimeField class's resolveNode method, where insufficient input validation permits attackers to manipulate object references before operations are performed on them. The flaw constitutes a fundamental security weakness that enables arbitrary code execution when exploited, making it particularly dangerous in enterprise environments where PDF readers are frequently used. The vulnerability requires user interaction through visiting malicious web pages or opening compromised files, which aligns with common attack vectors described in the ATT&CK framework under initial access and execution techniques. The lack of proper null pointer validation creates a predictable attack surface that allows remote adversaries to inject malicious code that executes within the context of the Foxit Reader process, potentially leading to complete system compromise. This type of vulnerability is especially concerning given that PDF readers are commonly used for document exchange in business environments, making them prime targets for social engineering attacks. The vulnerability's exploitation pathway demonstrates how improper object handling in document processing software can create persistent security risks that extend beyond simple document rendering.
The technical implementation of this vulnerability exposes a fundamental flaw in the application's defensive programming practices, specifically violating secure coding principles that mandate object validation before operations. The TimeField class's resolveNode method fails to verify whether referenced objects exist or are properly initialized before attempting to perform operations on them, creating an exploitable condition that can be leveraged through carefully crafted PDF content. This weakness allows attackers to manipulate the application's execution flow by providing malicious input that causes the application to reference non-existent objects, leading to memory corruption and potential code execution. The vulnerability's impact is amplified by the fact that Foxit Reader operates with elevated privileges when processing documents, providing attackers with a direct path to execute malicious code within the application's security context. The issue's classification as a remote code execution vulnerability means that attackers can exploit it without requiring local system access, making it particularly dangerous in networked environments where PDF documents are commonly shared and opened. The vulnerability's exploitation typically involves crafting malicious PDF files that trigger the flawed TimeField processing path, which then leads to arbitrary code execution through the application's memory management mechanisms.
Organizations using Foxit Reader 9.2.0.9297 face significant operational risks from this vulnerability, as it provides attackers with a straightforward method to gain unauthorized access to systems through PDF-based attack vectors. The requirement for user interaction makes this vulnerability particularly challenging to defend against, as it relies on social engineering tactics to succeed in compromising systems. Security teams must implement comprehensive monitoring and response procedures to detect potential exploitation attempts, as the vulnerability can be used to establish persistent access to compromised systems. The vulnerability's presence in widely deployed software creates a substantial risk profile that extends beyond individual user compromise to potentially affect entire organizational networks. This type of vulnerability also impacts the software supply chain, as organizations may unknowingly distribute malicious content through legitimate PDF documents, creating a cascading effect of potential compromise. The exploitation of this vulnerability can lead to data exfiltration, system reconnaissance, and establishment of persistent backdoors, making it a high-priority target for both cybercriminals and nation-state actors. Organizations should consider the vulnerability's implications for compliance requirements, as successful exploitation could result in regulatory violations and security breaches that require extensive remediation efforts.
Mitigation strategies for CVE-2018-17653 should focus on immediate software updates and implementation of defensive measures that address the underlying object validation weakness. The most effective immediate solution involves upgrading to Foxit Reader versions that contain patches addressing this specific vulnerability, as provided by the vendor's security advisory. Organizations should implement network-based controls such as web application firewalls and content filtering systems to block access to known malicious PDF content, while also deploying endpoint protection solutions that can detect and prevent exploitation attempts. Security teams should establish monitoring procedures to detect unusual PDF processing activities that may indicate exploitation attempts, particularly focusing on anomalous memory access patterns or unexpected code execution within the Foxit Reader process. Additional defensive measures include implementing user education programs to raise awareness about phishing attacks that may deliver malicious PDF files, as well as establishing secure document handling procedures that minimize exposure to untrusted content. The vulnerability's nature suggests that organizations should also consider implementing sandboxing technologies that isolate PDF processing activities from core system functions, providing an additional layer of protection against potential exploitation. Regular vulnerability assessments should be conducted to identify similar validation weaknesses in other document processing applications, as this type of flaw is prevalent in software that handles complex document formats. Organizations should also ensure that their incident response procedures include specific protocols for handling PDF-based security incidents, as the exploitation of such vulnerabilities often requires specialized forensic analysis and remediation approaches.