nginx/Windows 1.3.x before 1.3.1 and 1.2.x before 1.2.1 allows remote attackers to bypass intended access restrictions and access restricted files via (1) a trailing . (dot) or (2) certain "$index_allocation" sequences in a request.
http://nginx.org/en/security_advisories.html
http://mailman.nginx.org/pipermail/nginx-announce/2012/000086.html