Cisco VPN 3000 Concentrator 2.2.x, and 3.x before 3.5.3, adds an "HTTPS on Public Inbound (XML-Auto)(forward/in)" rule but sets the protocol to "ANY" when the XML filter configuration is enabled, which ultimately allows arbitrary traffic to pass through the concentrator.

Cisco VPN 3000 Concentrator 2.2.x, 3.6(Rel), and 3.x before 3.5.5, allows remote attackers to cause a denial of service via a long user name.

The LAN-to-LAN IPSEC capability for Cisco VPN 3000 Concentrator 2.2.x, and 3.x before 3.5.4, allows remote attackers to cause a denial of service via an incoming LAN-to-LAN connection with an existing security association with another device on the remote network, which causes the concentrator to remove the previous connection.

Cisco VPN 3000 Concentrator before 2.5.2(F), with encryption enabled, allows remote attackers to cause a denial of service (reload) via a Windows-based PPTP client with the "No Encryption" option set.

Cisco Virtual Private Network (VPN) Client software 2.x.x, and 3.x before 3.5.1C, does not properly verify that certificate DN fields match those of the certificate from the VPN Concentrator, which allows remote attackers to conduct man-in-the-middle attacks.

Multiple RADIUS implementations do not properly validate the Vendor-Length of the Vendor-Specific attribute, which allows remote attackers to cause a denial of service (crash) via a Vendor-Length that is less than 2.

Buffer overflow in digest calculation function of multiple RADIUS implementations allows remote attackers to cause a denial of service and possibly execute arbitrary code via shared secret data.

ISC DHCP client program dhclient allows remote attackers to execute arbitrary commands via shell metacharacters.

Multiple buffer overflows in ISC DHCP Distribution server (dhcpd) 1.0 and 2.0 allow a remote attacker to cause a denial of service (crash) and possibly execute arbitrary commands via long options.