spf.c in Courier Mail Server does not properly handle DNS failures when looking up Sender Policy Framework (SPF) records, which could allow attackers to cause memory corruption.

authpam.c in courier-authdaemon for Courier Mail Server 0.37.3 through 0.52.1, when using pam_tally, does not call the pam_acct_mgmt function to verify that access should be granted, which allows attackers to authenticate to the server using accounts that have been disabled.