HTB: Barrier

Barrier is a Linux box with GitLab, Authentik, and Apache Guacamole. I’ll exploit a SAML signature bypass vulnerability in GitLab’s Ruby SAML library to forge a SAML assertion and log in as admin. From GitLab’s CI/CD variables, I’ll recover an Authentik API token and use it to create an admin account. With Authentik admin access, I’ll impersonate a user in Guacamole to get an SSH shell. From…