# Missing signature verification of JWT

## Overview

* **Rule ID**: `java_lang_jwt_verification_bypass`
* **Applicable Languages**: Java
* **Weakness ID**: CWE-347

## Description

Neglecting to verify the signature of JSON Web Tokens (JWTs) undermines the security of an application. Signature verification is essential to validate the authenticity and integrity of JWTs. Without this verification, your application is vulnerable to token forgery and replay attacks, allowing attackers to manipulate or reuse tokens for unauthorized access.

## Remediation Guidelines

* **Avoid** using the `parse()` method to handle JWTs, as it does not verify the token's signature, creating a significant security vulnerability.

  ```java
  Jwts.parser().setSigningKey(JWT_PASSWORD).parse(accessToken); // unsafe
  ```
* **Use** the `parseClaimsJws()` method when working with JWTs. This method verifies the signature, thereby protecting against the manipulation of token data.

  ```java
  Jwts.parser().setSigningKey(JWT_PASSWORD).parseClaimsJws(accessToken);
  ```

## References

* [**JWT for Java Cheat Sheet**](https://cheatsheetseries.owasp.org/cheatsheets/JSON_Web_Token_for_Java_Cheat_Sheet.html)
* [**CWE-347: Improper Verification of Cryptographic Signature**](https://cwe.mitre.org/data/definitions/347.html)
* [**OWASP Top 10: A02:2021 - Cryptographic Failures**](https://owasp.org/Top10/A02_2021-Cryptographic_Failures/)

## Configuration

To omit this rule during a scan, and to provide you with continuous 24/7 code-level scanning, you can employ our [**SAST TOOL**](https://scopy.sec1.io/login)


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