# Cwe 287 Improper Authentication

> Use this skill when you need to remediate CWE-287 (Improper Authentication) vulnerabilities in Java code. Triggers on SAST findings, security reviews, or when fixing improper authentication issues.

- Skill: `developerscoffee/cwe-287-improper-authentication` (Agent Skill)
- Install (CLI): `npx skillmds@latest add developerscoffee/cwe-287-improper-authentication`
- Raw SKILL.md: https://api.skillmd.com/api/skills/developerscoffee/cwe-287-improper-authentication/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Security
- License: MIT
- Author: DevelopersCoffee (https://skillmd.com/u/developerscoffee)
- Updated: 2026-09-10
- Page: https://skillmd.com/skills/developerscoffee/cwe-287-improper-authentication

---


# CWE-287 Improper Authentication

## Description

Improper Authentication

Reference:
https://cwe.mitre.org/data/definitions/287.html


**OWASP Category**: A07:2021 – Identification and Authentication Failures


---

## Vulnerable Pattern


### ❌ Example 1: Vulnerable Pattern

```java
// VULNERABLE: No authentication check
@GetMapping("/admin/users")
public List<User> getUsers() {
    return userRepository.findAll();
}
```


**Why it's vulnerable:** This pattern is vulnerable to Improper Authentication




---

## Deterministic Fix


### ✅ Secure Implementation: Secure Implementation

```java
// SECURE: Require authentication
@GetMapping("/admin/users")
@PreAuthorize("hasRole('ADMIN')")
public List<User> getUsers(Authentication auth) {
    if (auth == null || !auth.isAuthenticated()) {
        throw new AccessDeniedException("Not authenticated");
    }
    return userRepository.findAll();
}
```


**Why it's secure:** Implements proper protection against Improper Authentication




---

## Detection Pattern

Look for these patterns in your codebase:


```bash
# Find controllers without security annotations
grep -rn "@GetMapping\\|@PostMapping" --include="*.java" -A5 | grep -v "@PreAuthorize\\|@Secured"
```



---

## Remediation Steps


1. Add authentication checks to all protected endpoints

2. Use Spring Security @PreAuthorize or @Secured annotations

3. Verify authentication status before processing requests


---

## Key Imports

```java

import org.springframework.security.access.prepost.PreAuthorize;

import org.springframework.security.core.Authentication;

```

---

## Verification

After remediation:


- Run SAST scanner to confirm vulnerability is resolved

- Review all instances of the vulnerable pattern

- Add unit tests that verify the secure implementation

- Check for similar patterns in related code


---

## Trigger Examples

```
Fix CWE-287 vulnerability
Resolve Improper Authentication issue
Secure this Java code against improper authentication
SAST reports CWE-287
```

---

## Common Vulnerable Locations

| Layer | Files | Patterns |
|-------|-------|----------|

| Controller | `*Controller.java` | User input handling |

| Service | `*Service.java` | Business logic |

| Repository | `*Repository.java` | Data access |


---

## References


- [CWE-287: Improper Authentication](https://cwe.mitre.org/data/definitions/287.html)


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**Source**: Generated by [Java CWE Security Skills Generator](https://github.com/DevelopersCoffee/java-cwe-security-skills)
**Last Updated**: 2026-03-07