An issue was discovered in Amazon AWS VPN Client 2.0.0. It is possible to include a UNC path in the OpenVPN configuration file when referencing file paths for parameters (such as auth-user-pass). When this file is imported and the client attempts to validate the file path, it performs an open operation on the path and leaks the user's Net-NTLMv2 hash to an external server. This could be exploited by having a user open a crafted malicious ovpn configuration file.

An issue was discovered in Amazon AWS VPN Client 2.0.0. A TOCTOU race condition exists during the validation of VPN configuration files. This allows parameters outside of the AWS VPN Client allow list to be injected into the configuration file prior to the AWS VPN Client service (running as SYSTEM) processing the file. Dangerous arguments can be injected by a low-level user such as log, which allows an arbitrary destination to be specified for writing log files. This leads to an arbitrary file write as SYSTEM with partial control over the files content. This can be abused to cause an elevation of privilege or denial of service.

The StartServiceCtrlDispatcher function in the cvpnd service (cvpnd.exe) in Cisco VPN client for Windows before 5.0.06.0100 does not properly handle an ERROR_FAILED_SERVICE_CONTROLLER_CONNECT error, which allows local users to cause a denial of service (service crash and VPN connection loss) via a manual start of cvpnd.exe while the cvpnd service is running.

Unspecified vulnerability in the VPN Client for Windows Graphical User Interface (GUI) (aka the VPN client dialer) in Cisco VPN Client for Windows 4.8.00.* and earlier, except for 4.7.00.0533, allows local authenticated, interactive users to gain privileges, possibly due to privileges of dialog boxes, aka bug ID CSCsd79265.

The Downloadable RADIUS ACLs feature in Cisco PIX and VPN 3000 concentrators, when creating an ACL on the Cisco Secure Access Control Server (CS ACS), generates a random internal name for an ACL that is also used as a hidden user name and password, which allows remote attackers to gain privileges by sniffing the username from the cleartext portion of a RADIUS session, then using the password to log in to another device that uses CS ACS.

Cisco VPN 3000 series Concentrator running firmware 4.1.7.A and earlier allows remote attackers to cause a denial of service (device reload or drop user connection) via a crafted HTTPS packet.

The do_change_cipher_spec function in OpenSSL 0.9.6c to 0.9.6k, and 0.9.7a to 0.9.7c, allows remote attackers to cause a denial of service (crash) via a crafted SSL/TLS handshake that triggers a null dereference.

OpenSSL 0.9.6 before 0.9.6d does not properly handle unknown message types, which allows remote attackers to cause a denial of service (infinite loop), as demonstrated using the Codenomicon TLS Test Tool.

Cisco VPN 3000 series concentrators and Cisco VPN 3002 Hardware Client 2.x.x through 3.6.7A allow remote attackers to cause a denial of service (slowdown and possibly reload) via a flood of malformed ICMP packets.

Cisco VPN 3000 series concentrators and Cisco VPN 3002 Hardware Client 2.x.x through 3.6.7 allows remote attackers to cause a denial of service (reload) via a malformed SSH initialization packet.