Buffer overflow in the spa_base64_to_bits function in Exim before 4.43, as originally obtained from Samba code, and as called by the auth_spa_client function, may allow attackers to execute arbitrary code during SPA authentication.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A11293
http://www.securityfocus.com/bid/12188
http://www.redhat.com/support/errata/RHSA-2005-025.html
http://www.idefense.com/application/poi/display?id=178&type=vulnerabilities
http://www.exim.org/mail-archives/exim-users/Week-of-Mon-20050103/msg00028.html
http://security.gentoo.org/glsa/glsa-200501-23.xml
http://marc.info/?l=bugtraq&m=110824870908614&w=2
http://ftp6.us.freebsd.org/pub/mail/exim/ChangeLogs/ChangeLog-4.44