Cisco AnyConnect Secure Mobility Client contains a vulnerability that could allow an unauthenticated, remote attacker to hijack WebLaunch sessions, which could allow the attacker to intercept sensitive information.
The vulnerability is due to the failure to perform certificate name checking in an X.509 certificate while using the WebLaunch feature. An unauthenticated, remote attacker could exploit the vulnerability by convincing a user to visit a malicious web page that accepts a crafted X.509 certificate. If successful, the attacker could intercept WebLaunch sessions, which could result in the disclosure of sensitive information that could be used to conduct further attacks.
Cisco has confirmed this vulnerability and released software updates.
Exploits of this vulnerability may require user interaction. An attacker could convince a user to visit a malicious website using a certificate that may be displayed as valid for a legitimate site. In addition, the user must be connected via the Cisco AnyConnect Secure Mobility Client using IPsec for an attacker to have a vector to exploit this vulnerability.
It is likely that an attacker would need access to an internal, private network to submit crafted X.509 certificates. This requirement may limit the possibility of an attack.
Cisco indicates through the CVSS score that proof-of-concept exploit code exists; however, the code is not known to be publicly available.