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  3. RealVNC Remote Authentication Bypass Vulnerability

RealVNC Remote Authentication Bypass Vulnerability

Risk

High

Date Discovered

May 15, 2006

Description

RealVNC is susceptible to an authentication-bypass vulnerability. This issue is due to a flaw in the authentication process of the affected package. Exploiting this issue allows attackers to gain unauthenticated, remote access to the VNC servers. RealVNC 4.1.1 is vulnerable to this issue; other versions may also be affected. UPDATE (May 25, 2006): Reports indicate that this issue is being actively exploited in the wild.

Technologies Affected

  • Cisco IP/VC 3540/DCS
  • RealVNC RealVNC Enterprise Edition 4.0
  • RealVNC RealVNC Enterprise Edition 4.1
  • RealVNC RealVNC Enterprise Edition 4.2
  • RealVNC RealVNC Enterprise Edition 4.2.2
  • RealVNC RealVNC Free Edition 4.0
  • RealVNC RealVNC Free Edition 4.1
  • RealVNC RealVNC Free Edition 4.1.1
  • RealVNC RealVNC Personal Edition 4.0
  • RealVNC RealVNC Personal Edition 4.1
  • RealVNC RealVNC Personal Edition 4.2
  • RealVNC RealVNC Personal Edition 4.2.2

Recommendations

Block external access at the network boundary, unless external parties require service.

If applicable, block access to the computer at the network perimeter. Allow only trusted computers and networks access to resources.

Communicate sensitive information over encrypted channels.

Ensure that access to affected VNC servers occurs only through strongly authenticated means such as VPNs. This will enforce that an extra level of authentication is required to access affected servers.
The vendor has released fixes to address this issue.

Credits

Steve Wiseman discovered this vulnerability.
Copyright © Symantec Corporation.
Permission to redistribute this alert electronically is granted as long as it is not edited in any way unless authorized by Symantec Security Response. Reprinting the whole or part of this alert in any medium other than electronically requires permission from secure@symantec.com.

Disclaimer
The information in the advisory is believed to be accurate at the time of publishing based on currently available information. Use of the information constitutes acceptance for use in an AS IS condition. There are no warranties with regard to this information. Neither the author nor the publisher accepts any liability for any direct, indirect, or consequential loss or damage arising from use of, or reliance on, this information.
Symantec, Symantec products, Symantec Security Response, and secure@symantec.com are registered trademarks of Symantec Corp. and/or affiliated companies in the United States and other countries. All other registered and unregistered trademarks represented in this document are the sole property of their respective companies/owners.

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