The ngx_http_parse_chunked function in http/ngx_http_parse.c in nginx 1.3.9 through 1.4.0 allows remote attackers to cause a denial of service (crash) and execute arbitrary code via a chunked Transfer-Encoding request with a large chunk size, which triggers an integer signedness error and a stack-based buffer overflow.
lists.fedoraproject.org/pipermail/package-announce/2013-May/105176.html
mailman.nginx.org/pipermail/nginx-announce/2013/000112.html
nginx.org/download/patch.2013.chunked.txt
packetstormsecurity.com/files/121675/Nginx-1.3.9-1.4.0-Denial-Of-Service.html
secunia.com/advisories/55181
security.gentoo.org/glsa/glsa-201310-04.xml
www.osvdb.org/93037
www.securityfocus.com/bid/59699
www.vnsecurity.net/2013/05/analysis-of-nginx-cve-2013-2028/
github.com/rapid7/metasploit-framework/pull/1834