The index_urlfetch function in index.c in Cyrus IMAP 2.3.x before 2.3.19, 2.4.x before 2.4.18, 2.5.x before 2.5.4 allows remote attackers to obtain sensitive information or possibly have unspecified other impact via vectors related to the urlfetch range, which triggers an out-of-bounds heap read.
https://docs.cyrus.foundation/imap/release-notes/2.5/x/2.5.4.html
https://docs.cyrus.foundation/imap/release-notes/2.4/x/2.4.18.html
https://docs.cyrus.foundation/imap/release-notes/2.3/x/2.3.19.html
https://cyrus.foundation/cyrus-imapd/commit/?id=c21e179c1f6b968fe69bebe079176714e511587b
https://cyrus.foundation/cyrus-imapd/commit/?id=07de4ff1bf2fa340b9d77b8e7de8d43d47a33921
http://www.openwall.com/lists/oss-security/2015/11/04/3
http://www.openwall.com/lists/oss-security/2015/09/30/3
http://www.openwall.com/lists/oss-security/2015/09/29/2
http://lists.opensuse.org/opensuse-updates/2015-09/msg00038.html
http://lists.opensuse.org/opensuse-updates/2015-09/msg00037.html
http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00000.html
http://lists.opensuse.org/opensuse-security-announce/2016-05/msg00066.html