The argument parser of the PARTIAL command in Cyrus IMAP Server 2.2.6 and earlier allows remote authenticated users to execute arbitrary code via a certain command ("body[p") that is treated as a different command ("body.peek") and causes an index increment error that leads to an out-of-bounds memory corruption.
https://www.ubuntu.com/usn/usn-31-1/
https://exchange.xforce.ibmcloud.com/vulnerabilities/18199
http://www.mandriva.com/security/advisories?name=MDKSA-2004:139
http://www.debian.org/security/2004/dsa-597
http://security.gentoo.org/glsa/glsa-200411-34.xml
http://security.e-matters.de/advisories/152004.html
http://secunia.com/advisories/13274/
http://marc.info/?l=bugtraq&m=110123023521619&w=2
http://asg.web.cmu.edu/cyrus/download/imapd/changes.html
http://asg.web.cmu.edu/archive/message.php?mailbox=archive.cyrus-announce&msg=143