CVE-2020-10904 in PhantomPDF
Summary
by MITRE
This vulnerability allows remote attackers to execute arbitrary code on affected installations of Foxit PhantomPDF 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 handling of U3D objects in PDF files. The issue results from the lack of proper validation of user-supplied data, which can result in a write past the end of an allocated object. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-10464.
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Analysis
by VulDB Data Team • 05/07/2026
CVE-2020-10904 represents a critical buffer overflow vulnerability affecting Foxit PhantomPDF version 9.7.1.29511 that enables remote code execution through maliciously crafted PDF files. This vulnerability resides in the Universal 3D (U3D) object handling mechanism within the PDF processing pipeline, where insufficient input validation leads to memory corruption. The flaw manifests when the application processes U3D content embedded in PDF documents without proper bounds checking, allowing an attacker to manipulate memory layout through crafted user-supplied data. This type of vulnerability directly maps to CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking allows writing beyond allocated memory regions. The security impact extends beyond simple memory corruption as it provides attackers with the ability to execute arbitrary code within the context of the current process, effectively compromising the entire PDF rendering environment.
The exploitation of this vulnerability requires user interaction through either visiting a malicious webpage hosting a crafted PDF or opening a specially prepared malicious file, making it a typical web-based attack vector that aligns with ATT&CK technique T1203. The attack surface is particularly concerning given that PDF readers are commonly used applications across enterprise and personal environments, making this vulnerability highly attractive to threat actors seeking persistent access. The write past the end of an allocated object creates a predictable memory corruption pattern that attackers can leverage to overwrite critical memory structures including return addresses, function pointers, or other control data. This memory corruption typically enables attackers to redirect execution flow and inject malicious code, potentially leading to full system compromise.
From a technical operational perspective, the vulnerability demonstrates a fundamental flaw in input sanitization and memory management practices within the Foxit PDF processing engine. The U3D object handling code path lacks proper validation of object size parameters and memory allocation boundaries, creating an exploitable condition that can be triggered through standard PDF document parsing operations. The vulnerability's remote execution capability means that attackers can deploy exploits through web-based delivery mechanisms without requiring physical access to target systems. This characteristic makes the vulnerability particularly dangerous in enterprise environments where users frequently access untrusted web content and email attachments containing malicious PDF documents. The attack can be amplified through social engineering campaigns targeting specific organizations or general phishing operations.
Organizations should implement immediate mitigations including updating to patched versions of Foxit PhantomPDF, implementing network-based protections such as web application firewalls to block suspicious PDF content, and deploying endpoint detection and response solutions to monitor for exploitation attempts. Security teams should also consider implementing user education programs to reduce the risk of successful exploitation through social engineering attacks. The vulnerability highlights the importance of proper input validation and memory safety practices in document processing applications, particularly those handling complex binary formats like PDFs. Additionally, organizations should conduct regular security assessments of their document processing infrastructure to identify similar vulnerabilities in other third-party applications that may be equally susceptible to buffer overflow attacks. The incident underscores the need for robust software security practices including code reviews, static analysis, and dynamic testing to prevent such memory corruption vulnerabilities from reaching production environments.