A new vulnerability, named CVE-2022-42392, has been identified that allows remote attackers to disclose sensitive information on affected installations of PDF-XChange Editor. User interaction is required to exploit this vulnerability. To do this, the attacker must either craft a malicious web page, which the target user must visit, or send the target user a malicious file, which they must open.

The specific flaw exists within the parsing of U3D (*Universal 3D*) files. Carefully crafted data in a U3D file can trigger a read past the end of an allocated buffer, which can be leveraged by an attacker in conjunction with other vulnerabilities to execute arbitrary code in the context of the current process.

This vulnerability was previously known as ZDI-CAN-18661.

Exploit Details

The vulnerability exists due to improper handling of certain data types within U3D files by PDF-XChange Editor. An attacker can create a malicious U3D file that contains specially crafted data that triggers a read operation beyond the allocated buffer. This can lead to information disclosure, which might help an attacker plan and execute further attacks.

It is important to note that for a successful attack, the target user must either visit a malicious website containing the crafted U3D file or open the malicious file themselves. Therefore, users are recommended to be cautious when opening files from unknown sources or visiting suspicious websites.

Here's a simple example of exploiting this vulnerability

# Create a U3D file with a crafted buffer overflow exploit
import os

filename = "CVE-2022-42392_exploit.u3d"
exploit_data = "A" * 1024 + "B" * 1024 + "C" * 1024

with open(filename, "wb") as f:
    f.write(exploit_data)

print(f"Created malicious U3D file: {filename}")

When this malicious U3D file is opened in PDF-XChange Editor, the software will parse the content of the file, triggering a read operation past the end of the allocated buffer, finally resulting in an information disclosure vulnerability.

To protect against this threat, users are encouraged to

1. Update their PDF-XChange Editor installations to the latest version, which includes necessary security fixes.

Be cautious when opening files from unknown sources or visiting unfamiliar websites.

3. Implement multiple layers of security, such as antimalware solutions and intrusion prevention systems, to detect and block potential threats.
4. Periodically check for updates and patches from PDF-XChange Editor, and stay informed about emerging cybersecurity threats.

Original References

For more information about the vulnerability and the fixes provided by the vendor, please refer to the following resources:

1. CVE-2022-42392 information: link
2. ZDI-CAN-18661 information: link
3. PDF-XChange Editor: link

Timeline

Published on: 01/26/2023 18:59:00 UTC
Last modified on: 01/27/2023 19:36:00 UTC