Some vulnerabilities have been reported in Cisco VPN Client, which can be exploited by malicious, local users to gain escalated privileges.

1) An error when using a VPN profile configured to use the Microsoft Dial-Up Networking Interface can be exploited to run arbitrary commands with the privileges of the LocalSystem account by enabling the "Start Before Logon" feature.

The vulnerability is reported in versions prior to 4.8.02.0010.

2) Incorrect permissions are set for cpvnd.exe during the Cisco VPN Client installation. This can be exploited by interactive users to run arbitary commands with the privileges of the LocalSystem account by replacing cvpnd.exe with an arbitrary file.

The vulnerability is reported in versions prior to 5.0.01.0600 and 64-bit version 5.0.7.0290.

Solution
Update to a fixed version (please see the vendor's advisory for details).
Further details available to Secunia VIM customers

Provided and/or discovered by
The vendor credits Dominic Beecher and Next Generation Security Software.

Changelog
Further details available to Secunia VIM customers

Original Advisory
Cisco:
http://www.cisco.com/warp/public/707/cisco-sa-20070815-vpnclient.shtml

Next Generation Security Software:
http://www.ngssoftware.com/advisories/high-risk-vulnerability-in-cisco-vpn-client-cvpndexe/
http://archives.neohapsis.com/archives/bugtraq/2011-07/0035.html

Deep Links
Links available to Secunia VIM customers