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AT&T WinVNC client authentication process vulnerable to man-in-the-middle attack

Vulnerability Note VU#303080

Original Release Date: 2001-06-13 | Last Revised: 2001-06-18

Overview

WinVNC's challenge/response mechanism can allow an intruder to obtain legitimate credentials from a valid client in order to gain unauthorized access to the server.

Description

AT&T WinVNC is a free package available from AT&T Labs Cambridge that allows an existing desktop of a PC to be available on the desktop of a remote host. If an intruder is able to eavesdrop traffic between the client and server with the ability to modify the data, they can gain access to the target system desktop, allowing local access to the system.

Impact

This vulnerability could allow a remote attacker to gain unauthorized access to the WinVNC service.

Solution

Tunnel WinVNC through software which provides strong authentication and secure communication. There is an example of this at http://www.uk.research.att.com/vnc/sshvnc.html.

Vendor Information

303080
Expand all

ATT

Updated:  June 14, 2001

Status

  Vulnerable

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

Please see http://www.kb.cert.org/vuls/id/303080

If you have feedback, comments, or additional information about this vulnerability, please send us email.


CVSS Metrics

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental N/A

References

Credit

Our thanks to CORE SDI for the information contained in their bulletin.

This document was written by Ian A. Finlay.

Other Information

CVE IDs: None
Severity Metric: 3.95
Date Public: 2001-01-23
Date First Published: 2001-06-13
Date Last Updated: 2001-06-18 23:41 UTC
Document Revision: 34

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