OpenConnect before 2.25 does not properly validate X.509 certificates, which allows man-in-the-middle attackers to spoof arbitrary AnyConnect SSL VPN servers via a crafted server certificate that (1) does not correspond to the server hostname or (2) is presented in circumstances involving a missing --cafile configuration option.

Double free vulnerability in OpenConnect before 1.40 might allow remote AnyConnect SSL VPN servers to cause a denial of service (application crash) or possibly have unspecified other impact via a crafted DTLS Cipher option during a reconnect operation.

Cisco Secure Desktop (CSD), when used in conjunction with an AnyConnect SSL VPN server, does not properly perform verification, which allows local users to bypass intended policy restrictions via a modified executable file.

The Cisco trial client on Linux for Cisco AnyConnect SSL VPN allows local users to overwrite arbitrary files via a symlink attack on unspecified temporary files.

Memory leak in the SSL VPN feature in Cisco IOS 12.4, 15.0, and 15.1, when HTTP port redirection is enabled, allows remote attackers to cause a denial of service (memory consumption) by improperly disconnecting SSL sessions, leading to connections that remain in the CLOSE-WAIT state, aka Bug ID CSCtg21685.

Cross-site scripting (XSS) vulnerability on the HP 3Com OfficeConnect Gigabit VPN Firewall 3CREVF100-73 with firmware before 1.0.13 allows remote attackers to inject arbitrary web script or HTML via unspecified vectors. NOTE: a separate XSS issue for HP System Management Homepage (SMH) was originally assigned CVE-2010-3010 due to a CNA error, but CVE-2010-3012 is the appropriate identifier for the SMH issue.

Unspecified vulnerability on Cisco Adaptive Security Appliances (ASA) 5580 series devices with software before 8.1(2) allows remote attackers to cause a denial of service (device crash) via vectors involving SSL VPN and PPPoE transactions, aka Bug ID CSCsm77958.

Cross-site scripting (XSS) vulnerability in wa/auth in PortWise SSL VPN 4.6 allows remote attackers to inject arbitrary web script or HTML via the reloadFrame parameter.

Stack-based buffer overflow in vpnconf.exe in TheGreenBow IPSec VPN Client 4.51.001, 4.65.003, and possibly other versions, allows user-assisted remote attackers to execute arbitrary code via a long OpenScriptAfterUp parameter in a policy (.tgb) file, related to "phase 2."

Multiple clientless SSL VPN products that run in web browsers, including Stonesoft StoneGate; Cisco ASA; SonicWALL E-Class SSL VPN and SonicWALL SSL VPN; SafeNet SecureWire Access Gateway; Juniper Networks Secure Access; Nortel CallPilot; Citrix Access Gateway; and other products, when running in configurations that do not restrict access to the same domain as the VPN, retrieve the content of remote URLs from one domain and rewrite them so they originate from the VPN's domain, which violates the same origin policy and allows remote attackers to conduct cross-site scripting attacks, read cookies that originated from other domains, access the Web VPN session to gain access to internal resources, perform key logging, and conduct other attacks. NOTE: it could be argued that this is a fundamental design problem in any clientless VPN solution, as opposed to a commonly-introduced error that can be fixed in separate implementations. Therefore a single CVE has been assigned for all products that have this design.

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.

The tgbvpn.sys driver in TheGreenBow IPSec VPN Client 4.61.003 allows local users to cause a denial of service (NULL pointer dereference and system crash) via a crafted request to the 0x80000034 IOCTL, probably involving an input or output buffer size of 0.

Cross-site scripting (XSS) vulnerability in the login interface (my.logon.php3) in F5 FirePass SSL VPN 5.5 through 5.5.2 and 6.0 through 6.0.3 allows remote attackers to inject arbitrary web script or HTML via a base64-encoded xcho parameter.

Unspecified vulnerability on Cisco Adaptive Security Appliances (ASA) 5500 Series devices 8.0 before 8.0(4)25 and 8.1 before 8.1(2)15, when an SSL VPN or ASDM access is configured, allows remote attackers to cause a denial of service (device reload) via a crafted (1) SSL or (2) HTTP packet.

Cisco Adaptive Security Appliances (ASA) 5500 Series and PIX Security Appliances 7.1(1) through 7.1(2)82, 7.2 before 7.2(4)27, 8.0 before 8.0(4)25, and 8.1 before 8.1(2)15, when AAA override-account-disable is entered in a general-attributes field, allow remote attackers to bypass authentication and establish a VPN session to an ASA device via unspecified vectors.

Format string vulnerability in Fortinet FortiClient 3.0.614, and possibly earlier, allows local users to execute arbitrary code via format string specifiers in the VPN connection name.

NOTE: this issue has been disputed by the vendor. Buffer overflow in the PKI Web Service in Check Point Firewall-1 PKI Web Service allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a long (1) Authorization or (2) Referer HTTP header to TCP port 18624. NOTE: the vendor has disputed this issue, stating "Check Point Security Alert Team has analyzed this report. We've tried to reproduce the attack on all VPN-1 versions from NG FP2 and above with and without HFAs. The issue was not reproduced. We have conducted a thorough analysis of the relevant code and verified that we are secure against this attack. We consider this attack to pose no risk to Check Point customers." In addition, the original researcher, whose reliability is unknown as of 20090407, also states that the issue "was discovered during a pen-test where the client would not allow further analysis.

Memory leak in the Cisco Tunneling Control Protocol (cTCP) encapsulation feature in Cisco IOS 12.4, when an Easy VPN (aka EZVPN) server is enabled, allows remote attackers to cause a denial of service (memory consumption and device crash) via a sequence of TCP packets.

Check Point VPN-1 R55, R65, and other versions, when Port Address Translation (PAT) is used, allows remote attackers to discover intranet IP addresses via a packet with a small TTL, which triggers an ICMP_TIMXCEED_INTRANS (aka ICMP time exceeded in-transit) response containing an encapsulated IP packet with an intranet address, as demonstrated by a TCP packet to the firewall management server on port 18264.

Apple iPhone OS 1.0 through 2.1 and iPhone OS for iPod touch 1.1 through 2.1 changes the encryption level of PPTP VPN connections to a lower level than was previously used, which makes it easier for remote attackers to obtain sensitive information or hijack a connection by decrypting network traffic.