CVE-2017-10994 in Foxit Reader
Summary
by MITRE
Foxit Reader before 8.3.1 and PhantomPDF before 8.3.1 have an Arbitrary Write vulnerability, which allows remote attackers to execute arbitrary code via a crafted document.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 12/31/2020
The vulnerability identified as CVE-2017-10994 represents a critical arbitrary write flaw affecting Foxit Reader versions prior to 8.3.1 and PhantomPDF versions prior to 8.3.1. This security weakness stems from insufficient input validation within the PDF processing engine of these applications, creating a pathway for malicious actors to manipulate memory structures through specially crafted PDF documents. The vulnerability operates at the core level of document parsing, where the applications fail to properly sanitize user-supplied data before writing it to memory locations, thereby enabling attackers to overwrite critical system components or inject malicious code directly into the application's execution flow.
From a technical perspective, this arbitrary write vulnerability falls under the CWE-787 weakness category, which specifically addresses out-of-bounds writes in software systems. The flaw manifests when the vulnerable applications process malformed PDF objects that contain crafted memory addresses and data payloads. Attackers can exploit this by creating PDF documents that trigger buffer overflow conditions or memory corruption scenarios, allowing them to write arbitrary data to memory locations that should remain protected. The vulnerability is particularly dangerous because it can be triggered remotely through web-based attacks or email attachments, requiring no local privileges or user interaction beyond opening the malicious document.
The operational impact of CVE-2017-10994 extends far beyond simple code execution, as it provides attackers with a complete code injection vector that can be leveraged for privilege escalation and system compromise. When successfully exploited, the vulnerability enables attackers to execute arbitrary code within the context of the Foxit Reader or PhantomPDF process, potentially leading to full system compromise if the application runs with elevated privileges. This aligns with the ATT&CK technique T1059.007 for command and scripting interpreter, as attackers can use the arbitrary code execution capability to run malicious commands, and T1068 for exploit for privilege escalation, since the vulnerability can be used to gain higher system privileges. The remote exploitation nature of this flaw means that organizations are vulnerable even when users simply browse the web or open email attachments, making it particularly attractive to threat actors conducting large-scale attacks.
Organizations affected by this vulnerability should immediately implement patch management protocols to upgrade to Foxit Reader 8.3.1 or later versions, as well as PhantomPDF 8.3.1 or later. Additional mitigations include implementing strict PDF file validation policies, deploying sandboxing solutions for PDF processing, and configuring web browsers to prompt users before opening PDF files from untrusted sources. Network-level defenses such as web application firewalls and content filtering solutions can help prevent malicious PDF documents from reaching end users, while endpoint protection solutions should be configured to monitor for suspicious file execution patterns. Security teams should also consider implementing user education programs to reduce the risk of social engineering attacks that might deliver malicious PDF files, and maintain comprehensive incident response procedures that account for potential exploitation of this vulnerability.