CVE-2020-13699

TeamViewer Desktop for Windows before 15.8.3 does not properly quote its custom URI handlers. A malicious website could launch TeamViewer with arbitrary parameters, as demonstrated by a teamviewer10: —play URL. An attacker could force a victim to send an NTLM authentication request and either relay the request or capture the hash for offline password cracking. This affects teamviewer10, teamviewer8, teamviewerapi, tvchat1, tvcontrol1, tvfiletransfer1, tvjoinv8, tvpresent1, tvsendfile1, tvsqcustomer1, tvsqsupport1, tvvideocall1, and tvvpn1. The issue is fixed in 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.

Recent assessments:

bwatters-r7 at August 06, 2020 11:59am UTC reported:

There is a vulnerability in Teamviewer that will attempt to access a remote SMB site when a user visits a malicious website. Part of a smb handshake involves the exchange of credentials. The SMB handshake would contain the username and hashed password of the user. Attackers could redirect the connection with something like responder and/or store the hash for later cracking.
Affected versions are 8 -15.8.2; 15.8.3 is the first patched version. Administrators should patch immediately of attempt to disable SMB connections from local networks if possible.

Assessed Attacker Value: 3
Assessed Attacker Value: 3Assessed Attacker Value: 3