Troubleshooting VIP Integration with PAM using RADIUS Authentication (Root Causes and Checklist for Diagnosis)

Products

• VIP Service

Issue/Introduction

When integrating VIP with PAM (Privileged Access Manager) using RADIUS authentication, you encounter errors from the VIP Validation Server, despite multiple configuration attempts.

ERROR "2024-10-10 10:55:03.627 GMT+0200" <IP-Address> VIP-Validation-Server:1812 0 0 "text=VSValidationPacketizerProcess() -- Can't get password attribute" Thread-5628 VSValidationPacketizer.cpp

ERROR "2024-10-10 10:55:03.627 GMT+0200" <IP-Address> VIP-Validation-Server:1812 0 0 "text=VSValidationServer._sendResponse() -- Unexpected error code [-1] after authentication for [149_<IP-Adress_49487]. Discarding the request." Thread-5628 VSValidationServer.cpp

These errors occur when configuring two-factor authentication for PAM using Symantec VIP Enterprise Gateway with RADIUS authentication.

Environment

VIP Service

Resolution

1. Authentication Mode Misconfiguration

VIP Enterprise Gateway supports two distinct authentication modes for integration with PAM:

• User ID – LDAP Password – Security Code (ULO): This mode requires users to authenticate with a combination of their user ID, LDAP password, and VIP security code (OTP).
• User ID – Security Code (UO): In this mode, users authenticate with their user ID and VIP security code only.

Make sure both PAM and VIP configurations are aligned to the chosen mode.

PAM Authentication Methods:

• LDAP+RADIUS: Use this for ULO mode, where LDAP password and RADIUS OTP are needed.
• RADIUS: Use this for UO mode, where only the RADIUS OTP is required.

Action: Ensure you select the correct authentication mode on both PAM and VIP Gateway.

2. PAM Client Login Fields

• Authentication Type “RADIUS”: Users should enter their VIP OTP in the "Password" field.
• Authentication Type “LDAP+RADIUS”: Users should enter their LDAP password in the "Password" field and the VIP OTP in the "RADIUS Password" field.

Action: Verify correct entry of user credentials according to the selected authentication method.

3. First Factor Checkbox in VIP Validation Server

The "Use First Factor" checkbox in the RADIUS validation server configuration affects the authentication flow:

• For ULO: This option should be checked, as both the LDAP password and OTP are required.
• For UO: This option should remain unchecked, as only the OTP is used.

Action: Confirm the correct checkbox selection in VIP Validation Server based on your chosen configuration (ULO or UO).

4. Debugging VIP Enterprise Gateway Logs

Enable debugging logs for the RADIUS service on the VIP Enterprise Gateway to capture detailed packet processing information. This will help in diagnosing errors that occur during validation.

Action: Refer to this VIP Enterprise Gateway Troubleshooting Guide to enable and analyze logs.

5. Check for VIP RADIUS Vulnerabilities

Ensure that you have applied the latest security patches, including any addressing CVE-2024-3596.

Action: Review the RADIUS Protocol Vulnerability Advisory for Symantec VIP.

Solution

After ensuring the correct configurations, if you still face issues, particularly the error PAM-CMN-0949: RADIUS user is not registered, this could be due to missing user registration in PAM.

Refer to this article for the fix: Symantec PAM RADIUS User Registration Issue.

Additional Information

Additional Recommendations

• Ensure that the VIP Enterprise Gateway’s LDAP connection is correctly configured if you are using the ULO mode.
• Test the connectivity between PAM and VIP Gateway, ensuring there are no firewall restrictions or networking issues.