SafeNet VPN client allows remote attackers to cause a denial of service and possibly execute arbitrary code via crafted Internet Key Exchange (IKE) response packets, possibly involving buffer overflows using (1) a large Security Parameter Index (SPI) field, (2) a large number of payloads, or (3) a long payload.

Memory leak in the (1) httpd, (2) nntpd, and (3) vpn driver in VelociRaptor 1.0 allows remote attackers to cause a denial of service (memory consumption) via an unknown method.

Dynamic VPN Configuration Protocol service (DVCP) in Watchguard Firebox firmware 5.x.x allows remote attackers to cause a denial of service (crash) via a malformed packet containing tab characters to TCP port 4110.

Cisco VPN 3000 Concentrator 3.6(Rel) and earlier, and 2.x.x, when configured to use internal authentication with group accounts and without any user accounts, allows remote VPN clients to log in using PPTP or IPSEC user authentication.

HTML interface for Cisco VPN 3000 Concentrator 2.x.x and 3.x.x before 3.0.3(B) allows remote attackers to cause a denial of service (CPU consumption) via a long URL request.

Information leaks in Cisco VPN 3000 Concentrator 2.x.x and 3.x.x before 3.5.4 allow remote attackers to obtain potentially sensitive information via the (1) SSH banner, (2) FTP banner, or (3) an incorrect HTTP request.

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 VPN 3000 Concentrator 2.2.x, and 3.x before 3.5.1, allows restricted administrators to obtain user passwords that are stored in plaintext in HTML source code.

Cisco VPN 3000 Concentrator 2.2.x, and 3.x before 3.5.2, allows restricted administrators to obtain certificate passwords that are stored in plaintext in the HTML source code for Certificate Management pages.

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, and 3.x before 3.5.3, allows remote attackers to obtain potentially sensitive information without authentication by directly accessing certain HTML pages.

Cisco VPN 3000 Concentrator 2.2.x, and 3.x before 3.5.3, allows remote attackers to cause a denial of service (crash) via a long (1) username or (2) password to the HTML login interface.

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 2.2.x, 3.6(Rel), and 3.x before 3.5.5, allows remote attackers to cause a denial of service via (1) malformed or (2) large ISAKMP packets.

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.

VPN Server module in Linksys EtherFast BEFVP41 Cable/DSL VPN Router before 1.40.1 reduces the key lengths for keys that are supplied via manual key entry, which makes it easier for attackers to crack the keys.

Cisco VPN 5000 series concentrator hardware 6.0.21.0002 and earlier, and 5.2.23.0003 and earlier, when using RADIUS with a challenge type of Password Authentication Protocol (PAP) or Challenge, sends the user password in cleartext in a validation retry request, which could allow remote attackers to steal passwords via sniffing.

Buffer overflow in the vpnclient program for UNIX VPN Client before 3.5.2 allows local users to gain administrative privileges via a long profile name in a connect argument.

CIPE VPN package before 1.3.0-3 allows remote attackers to cause a denial of service (crash) via a short malformed packet.