Cisco VPN client for Windows versions prior to 5.0.06.0100 contain an issue that may cause the cvpnd service to terminate.
The Cisco VPN client for Windows uses the cvpnd.exe binary as the service process that is bound to the Service Control Manager of the system. This application is not designed to be run from the command line.
The cvpnd service improperly implements the StartServiceCtrlDispatcher function, which could cause a running instance of the service to terminate; this termination leads to the tear down of any active VPN session. This behavior occurs due to a failure to properly trap the ERROR_FAILED_SERVICE_CONTROLLER_CONNECT error, which indicates that a service binary has been executed as a console application.
Cisco has documented this issue in Cisco bug ID CSCsz49276.
Cisco has released updated software that resolves this issue.
Cisco customers with active contracts can obtain updates through the Software Center at the following link: Cisco. Cisco customers without contracts can obtain upgrades by contacting the Cisco Technical Assistance Center at 1-800-553-2447 or 1-408-526-7209 or via e-mail at firstname.lastname@example.org.
This issue was found and reported to Cisco by Alex Hernandez from Syb Information Security, Inc. Cisco PSIRT greatly appreciates the opportunity to work with researchers on security vulnerabilities and welcomes the opportunity to review and assist in product reports.