Portswigger
  • Portswigger
  • Server-Side Request Forgery
    • Server-Side Request Forgery (SSRF)
  • SSRF with filter bypass via open redirection vulnerability
  • Blind SSRF with out-of-band detection
  • Cross-Site Scripting
    • Cross-Site Scripting (XSS)
  • Reflected XSS into a JS string with angle brackets and double&single quotes HTML-encoded escape
  • XSS into a template literal w/ angle brackets, single, double quotes, backslash & backticks Escaped
  • Authentication
    • Authentication
  • Username enumeration via subtly different responses
  • 2FA broken logic
  • Username enumeration via response timing
  • Username enumeration via account lock
  • Password reset poisoning via middleware
  • Path Traversal
    • Path Traversal
  • File path traversal, traversal sequences stripped with superfluous URL-decode
  • File path traversal, traversal sequences blocked with absolute path bypass
  • Business Logic Vulnerabilities
    • Business Logic Vulnerabilities
  • Insufficient workflow validation
  • Inconsistent handling of exceptional input
  • Server-Side Template Injection
    • Server-Side Template Injection
  • Basic server-side template injection
  • Basic server-side template injection (code context)
  • SQL Injection
    • SQL Injection
    • Blind SQL injection with conditional responses
  • SQL injection UNION attack, retrieving data from other tables
  • SQL injection attack, listing the database contents on non-Oracle databases
  • API Testing
    • API Testing
  • Exploiting an API endpoint using documentation
  • Exploiting a mass assignment vulnerability
  • Finding and exploiting an unused API endpoint
  • JWT ATTACK
    • JWT Attack
    • JWT authentication bypass via unverified signature
  • JWT authentication bypass via jku header injection
  • JWT authentication bypass via flawed signature verification
  • HTTP HOST HEADER ATTACKS
    • HTTP Host header attacks
  • Basic password reset poisoning
  • Host header authentication bypass
  • No SQL Injection
    • NoSQL Injection
  • Detecting NoSQL injection
  • Exploiting NoSQL operator injection to bypass authentication
  • Exploiting NoSQL injection to extract data
  • FILE UPLOAD VULNERABILITIES
    • File Upload Vulnerabilities
  • Web shell upload via obfuscated file extension
  • OAuth Authentication
    • OAuth Authentication
  • OAuth account hijacking via redirect_uri
  • ACCESS CONTROL VULNERABILITIES
    • Access Control Vulnerabilities
  • User ID controlled by request parameter with data leakage in redirect
  • User ID controlled by request parameter with password disclosure
  • User role controlled by request parameter
  • User role can be modified in user profile
  • URL-based access control can be circumvented
  • INFORMATION DISCLOSURE VULNERABILITIES
    • Information Disclosure Vulnerabilities
  • Information disclosure in version control history
  • XML external entity injection
    • XML External Entity (XXE) Injection
  • Exploiting XXE using external entities to retrieve files
  • Exploiting blind XXE to retrieve data via error messages
  • Blind XXE with out-of-band interaction
  • Blind XXE with out-of-band interaction via XML parameter entities
  • OS COMMAND INJECTION
    • OS Command Injection
  • Blind OS command injection with out-of-band data exfiltration
  • PROTOTYPE POLLUTION
    • Prototype Pollution
  • Privilege escalation via server-side prototype pollution
  • WEB CACHE POISONING
    • Web Cache Poisoning
  • Web cache poisoning via an unkeyed query parameter
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JWT authentication bypass via flawed signature verification

Link:https://portswigger.net/web-security/jwt/lab-jwt-authentication-bypass-via-flawed-signature-verification

PreviousJWT authentication bypass via jku header injectionNextHTTP Host header attacks

Last updated 3 months ago

Description:

This lab uses a JWT-based mechanism for handling sessions. The server is insecurely configured to accept unsigned JWTs.

To solve the lab, modify your session token to gain access to the admin panel at /admin, then delete the user carlos.

You can log in to your own account using the following credentials: wiener:peter

Preparation:

  • Install JSON Web Tokens on Burp Suite extension

Proof of concept:

  1. Lakukan analisa pada web target menggunakan akun testing

  2. Akses halaman /admin

  3. Terlihat halaman admin hanya dapat diakses menggunakan akun administrator. Lakukan percobaan modifikasi JWT menggunakan extension JSON Web Tokens yang sebelumnya telah diinstal dengan cara kirim request pada saat mengakses halaman /admin ke burp suite repater. Jika sudah, buka tab JSON Web Tokens

  4. Pada header JWT terdapat parameter alg dengan nilai RS256. Ubah nilai pada paramter alg tersebut menjadi none dengan cara pada drop-down Alg None Attack pilih Alg: none. Selanjutnya, pada payload terdapat parameter sub dengan nilai wiener / username yang sedang login. Ubah nilai pada parameter tersebut menjadi administrator

  5. Selanjutnya, kirim kembali request tersebut dan dapat dilihat halaman /admin berhasil diakses dengan ditandai dengan response 200 OK

  6. Untuk menyelesaikan tangtangan pada lab ini, hapus user carlos

Thanks, Stay Ethical & Happy Hacking! 🍻