Cisco Adaptive Security Appliance VPN SAML Authentication Bypass Vulnerability (cisco-sa-20190501-asaftd-saml-vpn)
Medium Nessus Plugin ID 128063
SynopsisThe remote device is missing a vendor-supplied security patch
DescriptionAccording to its self-reported version the Cisco Adaptive Security Appliance (ASA) software running on the remote device is affected by an authentication bypass vulnerability in the implementation of Security Assertion Markup Language (SAML) 2.0 Single Sign-On (SSO) for Clientless SSL VPN (WebVPN) and AnyConnect Remote Access VPN.
The vulnerability is due to improper credential management when using NT LAN Manager (NTLM) or basic authentication. An attacker could exploit this vulnerability by opening a VPN session to an affected device after another VPN user has successfully authenticated to the affected device via SAML SSO. A successful exploit could allow the attacker to connect to secured networks behind the affected device.
Please see the included Cisco BID and Cisco Security Advisory for more information.
SolutionUpgrade to the relevant fixed version referenced in Cisco bug ID CSCvn72570.