CVE-2002-0241

Vulnerability

NDSAuth.DLL in Cisco Secure Authentication Control Server (ACS) version 3.0.1 does not validate the Expired or Disabled state of users in the Novell Directory Services (NDS) during authentication [1]. This allows users whose accounts have been disabled or expired to successfully authenticate to the server, bypassing intended access controls.

Exploitation

An attacker who possesses valid NDS credentials for an account that has been disabled or expired can authenticate to the Cisco Secure ACS server without any additional privileges or network position beyond normal network access [1]. No user interaction or race condition is required; the attacker simply attempts to log in using the affected authentication path.

Impact

Successful exploitation grants the attacker unauthorized access to the Cisco Secure ACS server, potentially allowing them to gain network access or resources that should have been blocked due to account status [1]. The compromise is limited to the authentication bypass; the attacker does not gain elevated privileges beyond what the disabled/expired account originally had.

Mitigation

Cisco has published a security advisory and recommends upgrading to a fixed version of Cisco Secure ACS [1]. The advisory provides details on obtaining the patch. No workaround is documented in the available references. Users should apply the vendor-supplied fix as soon as possible.