Payroll blocked: the old servers can no longer call the payment service, “certificate expired”

The ml-paie-01 server (CentOS 7.9, maintained through the internal extended support repository ml-centos7-els) computes the pay of the trainers of the MasterLinux school and sends the transfer orders to the internal service https://paiement.masterlinux.lab (run by the security team, certificate issued by a public authority and renewed on 18 September).

Since 07:00 this morning, the scheduled export ml-paie-export fails on every attempt. The 20 October transfers (salaries of 214 trainers) must leave before 12:00, the bank's cut-off time. Two other old CentOS 7 servers (archiving and document management) report the same error.

What the team has already seen: from a browser or from ml-web-01 (Ubuntu 24.04), the service answers normally. The security team states that “the certificate is valid until January” and that nothing has changed on their side since September.

You are logged in as ops (sudo) on ml-paie-01. Find out why only the old servers fail and fix it without disabling certificate verification.