From CVS bug database, a comment from Brian Murphy (Sat Apr 30 04:43:28) says that CVS pam now requires a session line. Currently, CVS's PAM file contains only auth and account. With only those, trying to use CVS (login works, but nothing else) results in an error: PAM open session error: System error After adding the line "session include system-auth" in /etc/pam.d/cvs, CVS works fine again.
fixed in cvs.
*** Bug 72251 has been marked as a duplicate of this bug. ***