CVE-2020-13699 : Exploit Details and Defense Strategies

TeamViewer Desktop for Windows before 15.8.3 has a vulnerability that allows a malicious website to launch TeamViewer with arbitrary parameters, potentially leading to NTLM authentication request interception.

Understanding CVE-2020-13699

This CVE involves a security issue in TeamViewer Desktop for Windows that could be exploited by a malicious actor to intercept NTLM authentication requests.

What is CVE-2020-13699?

TeamViewer Desktop for Windows prior to version 15.8.3 does not properly handle custom URI handlers, enabling a malicious website to execute TeamViewer with arbitrary parameters. This could result in the interception of NTLM authentication requests.

The Impact of CVE-2020-13699

The vulnerability could allow an attacker to force a victim to send an NTLM authentication request, which could then be intercepted for potential offline password cracking.

Technical Details of CVE-2020-13699

This section provides more technical insights into the vulnerability.

Vulnerability Description

The issue arises from TeamViewer's improper handling of custom URI handlers, allowing malicious websites to launch TeamViewer with arbitrary parameters.

Affected Systems and Versions

Affected versions: teamviewer10, teamviewer8, teamviewerapi, tvchat1, tvcontrol1, tvfiletransfer1, tvjoinv8, tvpresent1, tvsendfile1, tvsqcustomer1, tvsqsupport1, tvvideocall1, and tvvpn1
Fixed versions: 8.0.258861, 9.0.258860, 10.0.258873, 11.0.258870, 12.0.258869, 13.2.36220, 14.2.56676, 14.7.48350, and 15.8.3

Exploitation Mechanism

The vulnerability can be exploited by crafting a malicious website that triggers TeamViewer with specific parameters, leading to potential interception of NTLM authentication requests.

Mitigation and Prevention

Protecting systems from CVE-2020-13699 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update TeamViewer to version 15.8.3 or the latest available patch to mitigate the vulnerability.
Avoid clicking on suspicious links or visiting untrusted websites to minimize the risk of exploitation.

Long-Term Security Practices

Regularly update software and applications to ensure the latest security patches are in place.
Educate users about the risks of interacting with unknown or unverified websites.

Patching and Updates

Ensure that all systems running TeamViewer are updated to version 15.8.3 or later to address the vulnerability.