Server-side request forgery vulnerability (SSRF)

[kkin77]

Describe the bug
Server-side request forgery vulnerability (SSRF)

To Reproduce
Steps to reproduce the behavior:
1.go to 'acp/acp.php?tn=pages&sub=index'
2. Enter the intranet address in the box to request
3. Can make a request to the intranet

Screenshots

request packet

Locate the vulnerable code /acp/core/pages.index.php
The start_index parameter calls the function fc_crawler

Tracing the fc_crawler function
Locate the vulnerable code /acp/core/functions_index.php

Continue to track the fc_loadSourceCode function

dict protocol for request

dict://ip:port

Use gopher protocol for request
gopher://192.168.172.114:9333/aaaaa

Led to the SSRF vulnerability

Desktop (please complete the following information):

• OS: MacOS
• Browser all
• Version last version

[patkon]

I'm a little at a loss about this problem. I hope checking the starting point fixes the problem?

[kkin77]

Sorry, I haven’t seen it these days, you can fix it like this
The port for restricting requests can only be port 80, and only HTTP and HTTPS requests are allowed.
Restrict the intellectual property that cannot access the intranet to prevent attacks on the intranet.
Prohibit 302, 301 jump