Gentoo has reported this issue via vendor-sec on 2004-10-05 Libsasl honors the environment variable SASL_PATH blindly, allowing a local user to compile a "library" locally that is executed with the EID of SASL when anything calls libsasl.
I've uploaded the upstream patch as attachment 104781 [details]
removing embargo
Gentoo in the same advisory that corrected CAN-2004-0884 http://www.gentoo.org/security/en/glsa/glsa-200410-05.xml mentioned also a buffer overflow: "Cyrus-SASL contains a remote buffer overflow in the digestmda5.c file." Does this overflow affect FC? I can not find what it was.
Looks like it's fixed in 2.1.19: http://asg.web.cmu.edu/archive/message.php?mailbox=archive.cyrus-sasl&msg=6078