The http_request_split_value function in request.c in lighttpd before 1.4.32 allows remote attackers to cause a denial of service (infinite loop) via a request with a header containing an empty token, as demonstrated using the "Connection: TE,,Keep-Alive" header.
https://wiki.mageia.org/en/Support/Advisories/MGASA-2012-0345
https://exchange.xforce.ibmcloud.com/vulnerabilities/80213
http://www.securitytracker.com/id?1027802
http://www.openwall.com/lists/oss-security/2012/11/21/1
http://www.mandriva.com/security/advisories?name=MDVSA-2013:100
http://secunia.com/advisories/51298
http://secunia.com/advisories/51268
http://packetstormsecurity.org/files/118282/Simple-Lighttpd-1.4.31-Denial-Of-Service.html
http://marc.info/?l=bugtraq&m=141576815022399&w=2
http://lists.opensuse.org/opensuse-updates/2014-01/msg00051.html
http://lists.opensuse.org/opensuse-updates/2012-11/msg00044.html
http://download.lighttpd.net/lighttpd/security/lighttpd_sa_2012_01.txt
http://download.lighttpd.net/lighttpd/security/lighttpd-1.4.31_fix_connection_header_dos.patch