CRLF injection vulnerability in PHP 4.2.1 through 4.2.3, when allow_url_fopen is enabled, allows remote attackers to modify HTTP headers for outgoing requests by causing CRLF sequences to be injected into arguments that are passed to the (1) fopen or (2) file functions.
https://exchange.xforce.ibmcloud.com/vulnerabilities/10080
http://www.securityfocus.com/bid/5681
http://www.debian.org/security/2002/dsa-168
http://archives.neohapsis.com/archives/bugtraq/2002-09/0132.html
http://archives.neohapsis.com/archives/bugtraq/2002-09/0086.html