CVE-2021-45979 in Foxit
Summary
by MITRE • 01/04/2022
Foxit PDF Reader and PDF Editor before 11.1 on macOS allow remote attackers to execute arbitrary code via app.launchURL in the JavaScript API.
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Analysis
by VulDB Data Team • 01/06/2022
The vulnerability identified as CVE-2021-45979 represents a critical remote code execution flaw in Foxit PDF Reader and PDF Editor versions prior to 11.1 on macOS platforms. This security weakness resides within the JavaScript API implementation of the PDF processing software, specifically through the app.launchURL function which enables arbitrary code execution when processing maliciously crafted PDF documents. The flaw allows remote attackers to exploit this functionality without requiring local system access or user interaction, making it particularly dangerous in targeted attack scenarios.
The technical implementation of this vulnerability stems from insufficient input validation and sanitization within the JavaScript API of the Foxit PDF application. When the app.launchURL function processes user-supplied parameters, it fails to properly validate or sanitize the input, allowing attackers to inject malicious URLs or commands that can trigger arbitrary code execution on the victim's system. This behavior aligns with CWE-74, which describes improper neutralization of special elements in output used by a downstream component, and CWE-94, which covers improper control of generation of code. The vulnerability essentially allows attackers to bypass security boundaries that should normally prevent arbitrary code execution through PDF JavaScript functionality.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with complete control over the affected macOS systems. Once exploited, attackers can install malware, steal sensitive data, modify system files, or establish persistent backdoors. The remote nature of the attack means that victims can be compromised simply by opening a malicious PDF document, which could be delivered through email attachments, web downloads, or compromised websites. This makes the vulnerability particularly attractive to threat actors conducting large-scale phishing campaigns or targeted attacks against organizations. The attack surface is significantly broadened as PDF documents are commonly used across various industries and are frequently opened without suspicion.
Organizations and individual users should immediately update to Foxit PDF Reader and PDF Editor version 11.1 or later to remediate this vulnerability. Security administrators should implement network-based protections such as PDF content filtering and web application firewalls to block potentially malicious PDF files before they reach end users. Additionally, user education regarding the dangers of opening PDF documents from untrusted sources remains critical. The mitigation strategy should also include monitoring for suspicious PDF file activities and implementing least privilege principles for PDF reader applications. From an ATT&CK framework perspective, this vulnerability maps to techniques involving execution through script interpreters and privilege escalation, with potential lateral movement opportunities once initial access is achieved. Regular security assessments and vulnerability scanning should be conducted to ensure all PDF processing software remains up to date with the latest security patches.