CVE-2020-10899 in Foxit
Summary
by MITRE
This vulnerability allows remote attackers to execute arbitrary code on affected installations of Foxit Reader 9.7.1.29511. 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 XFA templates. 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-10132.
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Analysis
by VulDB Data Team • 05/06/2025
The vulnerability identified as CVE-2020-10899 represents a critical remote code execution flaw in Foxit Reader version 9.7.1.29511 that demonstrates the classic symptoms of a null pointer dereference vulnerability. This weakness resides within the XFA (XML Forms Architecture) template processing functionality of the PDF reader, making it particularly dangerous as it can be triggered through web-based attacks. The vulnerability operates under the CWE-476 principle of null pointer dereference, where the application fails to validate object existence before attempting operations on it. The attack vector requires user interaction, meaning that victims must either visit a malicious webpage or open a specially crafted malicious file to trigger the exploit, which aligns with the ATT&CK technique T1203 for exploitation of web applications. This requirement for user interaction does not diminish the severity of the vulnerability, as social engineering campaigns can effectively target users to visit malicious sites.
The technical exploitation of this vulnerability occurs during the processing of XFA templates, which are used to create dynamic forms within PDF documents. When Foxit Reader encounters a malformed XFA template, it fails to properly validate whether certain objects exist before attempting to access or manipulate them. This validation gap allows an attacker to construct a malicious XFA template that, when processed by the vulnerable reader, causes the application to execute arbitrary code with the privileges of the current user process. The lack of proper input validation and object existence checking creates a pathway for attackers to bypass normal execution boundaries and potentially escalate privileges. The vulnerability essentially allows attackers to inject malicious code that executes within the same security context as the legitimate Foxit Reader application, which could lead to complete system compromise.
The operational impact of CVE-2020-10899 extends beyond simple remote code execution, as it represents a significant threat to enterprise security environments where PDF readers are commonly used for business documentation. Organizations that have not patched their Foxit Reader installations remain vulnerable to attacks that could result in data theft, system compromise, or the deployment of additional malware. The vulnerability's presence in a widely used PDF reader means that it could be exploited through various attack vectors including phishing emails, compromised websites, or malicious document sharing platforms. The fact that this vulnerability was tracked as ZDI-CAN-10132 indicates it was recognized by the security community as a legitimate threat requiring immediate attention and patching. Security teams must consider this vulnerability as part of their broader threat landscape, particularly in environments where users frequently open PDF documents from untrusted sources.
Mitigation strategies for CVE-2020-10899 should prioritize immediate patch deployment from Foxit Corporation, as this represents the most effective defense against exploitation. Organizations should implement network-based protections including web proxies that scan PDF content for malicious patterns, though this approach may not be sufficient to block all variants of the attack. Additional defensive measures include user education programs to reduce the likelihood of visiting malicious sites or opening suspicious files, as well as implementing application whitelisting policies that restrict execution of untrusted PDF files. Security monitoring should focus on detecting unusual PDF processing activities or attempts to access system resources that could indicate exploitation attempts. The vulnerability's classification under CWE-476 and its exploitation pattern align with ATT&CK techniques for privilege escalation and initial access, making it essential for security teams to monitor for these specific indicators of compromise in their network traffic and endpoint logs.