lighttpd before 1.4.33 does not check the return value of the (1) setuid, (2) setgid, or (3) setgroups functions, which might cause lighttpd to run as root if it is restarted and allows remote attackers to gain privileges, as demonstrated by multiple calls to the clone function that cause setuid to fail when the user process limit is reached.
download.lighttpd.net/lighttpd/security/lighttpd_sa_2013_02.txt
jvn.jp/en/jp/JVN37417423/index.html
lists.opensuse.org/opensuse-updates/2014-01/msg00049.html
marc.info/?l=bugtraq&m=141576815022399&w=2
secunia.com/advisories/55682
www.openwall.com/lists/oss-security/2013/11/12/4
kc.mcafee.com/corporate/index?page=content&id=SB10310
www.debian.org/security/2013/dsa-2795