Oh, this is routine tested, nice! It really looked like the Debian bug, but, as it turns out, it was probably caused by an outdated (or broken) vsftpd package from thefrontiergroup's PPA. Purging the package and reinstalling the official one fixed the issue. Thank you Robie!
** Changed in: vsftpd (Ubuntu) Status: Incomplete => Invalid -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to vsftpd in Ubuntu. https://bugs.launchpad.net/bugs/1326167 Title: [trusty] local user login broken: vsftpd: PAM audit_log_acct_message() failed: Operation not permitted To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/vsftpd/+bug/1326167/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs