The PDF XSS protection feature in ModSecurity before 2.5.8 allows remote attackers to cause a denial of service (Apache httpd crash) via a request for a PDF file that does not use the GET method.
https://www.redhat.com/archives/fedora-package-announce/2009-March/msg00529.html
https://www.redhat.com/archives/fedora-package-announce/2009-March/msg00487.html
https://exchange.xforce.ibmcloud.com/vulnerabilities/49211
http://www.vupen.com/english/advisories/2009/0703
http://www.securityfocus.com/bid/34096
http://security.gentoo.org/glsa/glsa-200907-02.xml
http://secunia.com/advisories/35687