Mike, If you deploy UltraVNC with the encryption enabled, this is not an issue. This is because the encryption plug-in begins encrypting traffic before the VNC authentication is transferred.
Link #1: http://www.vncscan.com/UltraVNC/Ultravnc_with_DSM.htm Link #2: http://msrc4plugin.home.comcast.net/index.html Thank you, Steve Bostedor http://www.vncscan.com -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of James Weatherall Sent: Tuesday, May 09, 2006 4:42 AM To: 'Mike Miller'; 'VNC List' Subject: RE: [EMAIL PROTECTED] vulnerability Hi Mike, If you are running UltraVNC servers that are directly accessible via untrusted networks, or by untrusted hosts, then this is potentially an extremely serious problem, since it appears that you only have to log on remotely a few times to a system for an attacker to have enough challenge-response data to crack the password. Needless to say, the information provided in the report is insufficient to say for sure. Note that this issue is specific to the UltraVNC project, and does not affect standard VNC or VNC-compatible servers. To connect securely to systems using standard Windows accounts, you may wish to consider VNC Enterprise Edition (http://www.realvnc.com/products/enterprise). Regards, Wez @ RealVNC Ltd. > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Mike Miller > Sent: 09 May 2006 07:18 > To: VNC List > Subject: [EMAIL PROTECTED] vulnerability > > What are your opinions on this? (below) How serious is it? > > Mike > > > ************************************************************** > *********** > @RISK: The Consensus Security Vulnerability Alert > May 8, 2006 > Vol. 5. Week 18 > ************************************************************** > *********** > > > Part II -- Comprehensive List of Newly Discovered Vulnerabilities from > Qualys (www.qualys.com) > > > 06.18.13 CVE: Not Available > Platform: Third Party Windows Apps > Title: UltraVNC Weak Challenge-Response Authentication > Description: UltraVNC is susceptible to a weak challenge-response > authentication vulnerability. This issue is due to the use of insecure > encryption during the authentication process of UltraVNC when > configured to utilize the Microsoft Logon authentication mechanism. > UltraVNC version 1.0.1 is vulnerable. > Ref: http://www.securityfocus.com/bid/17824 > _______________________________________________ > VNC-List mailing list > [email protected] > To remove yourself from the list visit: > http://www.realvnc.com/mailman/listinfo/vnc-list _______________________________________________ VNC-List mailing list [email protected] To remove yourself from the list visit: http://www.realvnc.com/mailman/listinfo/vnc-list _______________________________________________ VNC-List mailing list [email protected] To remove yourself from the list visit: http://www.realvnc.com/mailman/listinfo/vnc-list
