CVE-2019-13320 in Foxit
Summary
by MITRE
This vulnerability allows remote attackers to execute arbitrary code on affected installations of Foxit Reader 9.5.0.20723. 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 processing of AcroForms. 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-8814.
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Analysis
by VulDB Data Team • 01/03/2024
The vulnerability identified as CVE-2019-13320 represents a critical remote code execution flaw within Foxit Reader version 9.5.0.20723 that demonstrates a classic object validation weakness in document processing software. This vulnerability operates under the Common Weakness Enumeration framework as CWE-476, specifically addressing NULL pointer dereference conditions that occur when applications fail to validate object existence before operations. The flaw manifests during the processing of AcroForms, which are interactive form elements commonly used in pdf documents for data collection and user interaction. The vulnerability requires user interaction to be exploited, meaning that attackers must convince victims to visit malicious web pages or open compromised pdf files containing specially crafted AcroForm elements designed to trigger the vulnerable code path.
The technical implementation of this vulnerability stems from inadequate input validation within the pdf parsing engine of Foxit Reader. When processing AcroForm elements, the application fails to properly validate whether referenced objects exist within the document structure before attempting to perform operations on them. This validation gap creates a condition where an attacker can craft malicious pdf documents containing malformed AcroForm references that, when processed by the vulnerable software, cause the application to attempt operations on null or invalid object pointers. The resulting memory access violations can be manipulated by attackers to redirect execution flow and ultimately execute arbitrary code with the privileges of the currently running Foxit Reader process. This represents a significant escalation from a simple parsing error to a full remote code execution capability that can be leveraged for system compromise.
The operational impact of this vulnerability extends beyond simple document processing, as it provides attackers with a means to establish persistent access to systems through the exploitation of widely used pdf reader software. The vulnerability affects organizations that rely on Foxit Reader for document handling, creating potential attack vectors through phishing campaigns targeting document viewers or malicious websites hosting compromised content. According to ATT&CK framework categorization, this vulnerability maps to T1203 - Exploitation for Client Execution, where attackers leverage application vulnerabilities to execute code on target systems. The attack chain typically involves initial access through web browsing or document opening activities, followed by exploitation of the AcroForm processing flaw to achieve code execution. Organizations with extensive use of Foxit Reader across their network infrastructure face heightened risk, as the vulnerability can be exploited through multiple delivery mechanisms including email attachments, web downloads, and malicious document repositories.
Mitigation strategies for this vulnerability should prioritize immediate patching of Foxit Reader installations to the latest secure versions that address the object validation flaw. System administrators should implement application whitelisting policies to restrict execution of unauthorized pdf processing applications and deploy web application firewalls to filter malicious content. Network segmentation and user access controls should be reinforced to limit potential lateral movement if exploitation occurs. Security monitoring should include detection of unusual pdf processing activities and anomalous network connections that might indicate exploitation attempts. The vulnerability also highlights the importance of regular security assessments for document processing software and the need for comprehensive vulnerability management programs that can quickly identify and remediate similar flaws in third-party applications. Organizations should also consider implementing sandboxing technologies for pdf document handling and establishing incident response procedures specifically designed to address remote code execution vulnerabilities in commonly used software applications.