Mostly fixed thing! May occure in some handwritten web-servers

CRLF - Carriege Return (\r) Line Feed (\n) (or %0d %0a)

Inserting \r\n into URL allow attacker to:

• log splitting - to insert logs to server that may decieve administrator
• HTTP response slpitting - Allows to add HTTP headers to the HTTP response
  • XSS - www.target.com/%3f%0d%0aLocation:%0d%0aContent-Type:text/html%0d%0aX-XSS-Protection%3a0%0d%0a%0d%0a%3Cscript%3Ealert%28document.domain%29%3C/script%3E - disables XSS protection, set location to custom (but does it work without 302/201 status???), sets html content-type and injects javascript.
  • cookie injection
  • check another note

For example: GET /%0d%0aSet-Cookie:CRLFInjection=PreritPathak HTTP/1.1 Will add Set-Cookie:CRLFInjection=PreritPathak header to HTTP response