A use-after-free vulnerability (CVE-2022-32774) has been discovered in the JavaScript engine of Foxit Software's PDF Reader, specifically in version 12..1.12430. This vulnerability can lead to arbitrary code execution if a user accidentally opens a malicious PDF document crafted by an attacker. The vulnerability also exists if the user visits a specially-designed, malicious website with the Foxit browser plugin extension enabled.

Code Snippet

The vulnerability can be triggered through a specific JavaScript code sequence. The following code snippet demonstrates a PoC (Proof of Concept) example that could potentially cause the issue:

// The following code snippet demonstrates triggering the use-after-free vulnerability in Foxit PDF Reader 12..1.12430

var doc = app.activeDocs;
var num = doc.numPages;

// Prematurely deleting objects associated with pages
doc.deletePages(num - 1);

// Reusing previously freed memory (use-after-free) might lead to arbitrary code execution
var obj = doc.getPageNthWord(num - 1);

For more information about the vulnerability, including detailed analysis and source code, please refer to the following links:

1. Foxit PDF Reader - Use-after-free vulnerability (Official Foxit Security Advisory)
2. Foxit PDF Reader 12..1.12430 - JavaScript Engine Use-After-Free (Exploit Database Entry)

Exploit Details

To exploit this vulnerability, an attacker must craft a specifically designed PDF document that contains the malicious JavaScript code. When a user opens this PDF file with the vulnerable Foxit PDF Reader, the malicious code executes, causing previously freed memory to be reused. Consequently, this may lead to arbitrary code execution.

This can happen in two main ways

1. Via email or file sharing: The attacker can send the malicious PDF file to the target via email or any file-sharing service. If the user attempts to open the file using the vulnerable Foxit PDF Reader, the vulnerability is triggered, and arbitrary code execution could occur.

2. Via a malicious website with the browser plugin enabled: The attacker can create a malicious website containing the specially crafted PDF file. If the user visits this website using a browser with the Foxit browser plugin enabled, the vulnerability can also be triggered, allowing arbitrary code execution.

To mitigate this vulnerability, users are encouraged to update their Foxit PDF Reader software to the latest version as soon as possible. Disabling the browser plugin can also help prevent exploitation when visiting malicious websites. Always exercise caution when opening files from unknown sources or visiting unfamiliar websites.

For more details on the security implications of this vulnerability, and the possible steps one can take to address it, please see the Foxit Security Advisories page.

Timeline

Published on: 11/21/2022 16:15:00 UTC
Last modified on: 11/22/2022 19:01:00 UTC