CVE-2018-17657 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 gotoURL 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-6507.
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Analysis
by VulDB Data Team • 05/05/2020
CVE-2018-17657 represents a critical remote code execution vulnerability affecting Foxit Reader version 9.2.0.9297, classified under CWE-476 as a NULL Pointer Dereference. This vulnerability stems from inadequate input validation within the PDF reader's implementation of the gotoURL method, which is part of the host object handling mechanism. The flaw occurs when the application fails to verify whether an object exists before attempting operations on it, creating a dangerous condition where malicious code can be executed within the context of the current process. The vulnerability requires user interaction to be exploited, meaning attackers must convince victims to visit malicious web pages or open compromised PDF files containing crafted malicious content. This attack vector aligns with ATT&CK technique T1203, which involves exploiting vulnerabilities in software applications to gain unauthorized access and execute arbitrary code. The specific technical weakness lies in the improper validation of object references during PDF processing, allowing attackers to manipulate the application's behavior through crafted PDF files that trigger the vulnerable gotoURL method. When a user opens a malicious PDF, the application attempts to process the gotoURL command without proper object existence checks, leading to a potential buffer overflow or arbitrary code execution scenario.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with full control over the victim's system within the privileges of the Foxit Reader application. This represents a significant escalation risk since PDF readers often run with elevated privileges on modern operating systems, particularly when dealing with document processing and printing functions. The vulnerability's exploitation pathway demonstrates how seemingly benign PDF functionality can be weaponized through improper input validation, creating a persistent threat vector that can be leveraged for data exfiltration, system compromise, or further network infiltration. Organizations using Foxit Reader 9.2.0.9297 are particularly vulnerable as this version lacks proper bounds checking and object validation mechanisms that would normally prevent such exploitation scenarios.
Mitigation strategies for CVE-2018-17657 should focus on immediate patching of the affected Foxit Reader version, as well as implementing network-based controls to prevent access to known malicious PDF content. Security professionals should deploy web application firewalls and content filtering solutions that can detect and block suspicious PDF files containing malicious gotoURL operations. Additionally, user education and awareness programs should emphasize the dangers of opening untrusted PDF files from unknown sources, particularly those containing embedded JavaScript or external URL references. Organizations should also consider implementing sandboxing mechanisms for PDF processing and regularly monitoring for anomalous network traffic patterns that may indicate exploitation attempts. The vulnerability highlights the importance of proper defensive programming practices, including object validation and input sanitization, which are fundamental principles in secure software development and directly relate to ATT&CK techniques targeting application vulnerabilities for privilege escalation and code execution.