Second-order symlink vulnerability in eix-sync.in in Ebuild IndeX (eix) before 0.5.0_pre2 allows local users to overwrite arbitrary files via a symlink attack on the exi.X.sync temporary file, which is processed by the diff-eix program.
http://www.vupen.com/english/advisories/2005/2539
http://www.securityfocus.com/bid/15541
http://www.gentoo.org/security/en/glsa/glsa-200511-19.xml