A vulnerability in the implementation of Security Assertion Markup Language (SAML) Single Sign-On (SSO) authentication for Cisco AnyConnect Secure Mobility Client for Desktop Platforms, Cisco Adaptive Security Appliance (ASA) Software, and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to establish an authenticated AnyConnect session through an affected device running ASA or FTD Software. The authentication would need to be done by an unsuspecting third party.
The vulnerability exists because there is no mechanism for the ASA or FTD Software to detect that the authentication request originates from the AnyConnect client directly. An attacker could exploit this vulnerability by persuading a user to click a crafted link and authenticating using the company's Identity Provider (IdP). A successful exploit could allow the attacker to hijack a valid authentication token and use that to establish an authenticated AnyConnect session through an affected device running ASA or FTD Software.
Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.
This advisory is available at the following link: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180418-asaanyconnect ["https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180418-asaanyconnect"]