TITLE:
RealVNC Password Authentication Bypass Vulnerability

SECUNIA ADVISORY ID:
SA20107

VERIFY ADVISORY:
http://secunia.com/advisories/20107/

CRITICAL:
Highly critical

IMPACT:
Security Bypass

WHERE:
>From remote

SOFTWARE:
RealVNC 4.x
http://secunia.com/product/3719/

DESCRIPTION:
Steve Wiseman has reported a vulnerability in RealVNC, which can be
exploited by malicious people to bypass certain security
restrictions.

The vulnerability is caused due to an error within the handling of
VNC password authentication requests. This can be exploited to bypass
authentication and allows access to the remote system without
requiring knowledge of the VNC password.

The vulnerability has been reported in version 4.1.1. Other versions
may also be affected.

Note: Version 4.0 is reportedly not affected.

SOLUTION:
Update to Free Edition version 4.1.2 or Personal Edition/Enterprise
Edition version 4.2.3.
http://www.realvnc.com/download.html

PROVIDED AND/OR DISCOVERED BY:
Steve Wiseman

ORIGINAL ADVISORY:
RealVNC:
http://www.realvnc.com/products/free/4.1/release-notes.html
http://www.realvnc.com/products/personal/4.2/release-notes.html
http://www.realvnc.com/products/enterprise/4.2/release-notes.html

IntelliAdmin:
http://www.intelliadmin.com/blog/2006/05/security-flaw-in-realvnc-411.html
http://www.intelliadmin.com/blog/2006/05/vnc-flaw-proof-of-concept.html

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