Security Onion Installation Fails at 95%. Throws certificate relies on legacy Common Name field, use SANs or temporarily enable Common Name matching with GODEBUG=x509ignoreCN=0 Error

[0xabdi]

Here is the error it throws:

ubuntu@sensor:~/securityonion$ sudo cat /root/sosetup.log | grep ERROR
[ERROR   ] Failed to pull somanager:5000/security-onion-solutions/so-nginx:2.3.91: Error 500: Get "https://so2-manager:5000/v2/": x509: certificate relies on legacy Common Name field, use SANs or temporarily enable Common Name matching with GODEBUG=x509ignoreCN=0

Installation Steps I undertook:

1. git clone https://github.com/Security-Onion-Solutions/securityonion
2. cd securityonion
3. sudo bash so-setup-network

install type : "DISTRIBUTED"
node type : "SENSOR"

The error is thrown on the sensor where I want to do the installation. The sensor is running on an Ubuntu EC2 VM on AWS. The manager is hosted on an on-prem location. The connection between the two has been established over an openVPN connection.

[dougburks]

This looks similar to #6997 (comment).

What version of Ubuntu are you running on the manager and sensor?

[0xabdi]

Yes, it is similar #6997

We are running ubuntu 20 on the sensor and ubuntu 18 on the manager. Looks like the issue is related to openssl mismatch as mentioned on #6997

We are downgrading the sensor to ubuntu 18

[dougburks]

I've added a warning to the documentation:
https://docs.securityonion.net/en/2.3/installation.html

[0xabdi]

Alright,

Thanks @dougburks