Stack-based buffer overflow in the Curl_sasl_create_digest_md5_message function in lib/curl_sasl.c in curl and libcurl 7.26.0 through 7.28.1, when negotiating SASL DIGEST-MD5 authentication, allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a long string in the realm parameter in a (1) POP3, (2) SMTP or (3) IMAP message.
http://www.ubuntu.com/usn/USN-1721-1
http://www.securitytracker.com/id/1028093
http://www.securityfocus.com/bid/57842
http://www.oracle.com/technetwork/topics/security/cpujul2015-2367936.html
http://packetstormsecurity.com/files/120170/Slackware-Security-Advisory-curl-Updates.html
http://packetstormsecurity.com/files/120147/cURL-Buffer-Overflow.html
http://lists.fedoraproject.org/pipermail/package-announce/2013-February/099140.html
http://lists.apple.com/archives/security-announce/2013/Oct/msg00004.html