springboot-security

Spring Boot Security Review

Use when adding auth, handling input, creating endpoints, or dealing with secrets.

Authentication

• Prefer stateless JWT or opaque tokens with revocation list
• Use httpOnly, Secure, SameSite=Strict cookies for sessions
• Validate tokens with OncePerRequestFilter or resource server

@Component
public class JwtAuthFilter extends OncePerRequestFilter {
  private final JwtService jwtService;

  public JwtAuthFilter(JwtService jwtService) {
    this.jwtService = jwtService;
  }

@Override protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain chain) throws ServletException, IOException { String header = request.getHeader(HttpHeaders.AUTHORIZATION); if (header != null && header.startsWith("Bearer ")) { String token = header.substring(7); Authentication auth = jwtService.authenticate(token); SecurityContextHolder.getContext().setAuthentication(auth); } chain.doFilter(request, response); } }

## Authorization

- Enable method security: `@EnableMethodSecurity`
- Use `@PreAuthorize("hasRole('ADMIN')")` or `@PreAuthorize("@authz.canEdit(#id)")`
- Deny by default; expose only required scopes

## Input Validation

- Use Bean Validation with `@Valid` on controllers
- Apply constraints on DTOs: `@NotBlank`, `@Email`, `@Size`, custom validators
- Sanitize any HTML with a whitelist before rendering

## SQL Injection Prevention

- Use Spring Data repositories or parameterized queries
- For native queries, use `:param` bindings; never concatenate strings

## CSRF Protection

- For browser session apps, keep CSRF enabled; include token in forms/headers
- For pure APIs with Bearer tokens, disable CSRF and rely on stateless auth

```java
http
  .csrf(csrf -> csrf.disable())
  .sessionManagement(sm -> sm.sessionCreationPolicy(SessionCreationPolicy.STATELESS));

Secrets Management

• No secrets in source; load from env or vault
• Keep application.yml free of credentials; use placeholders
• Rotate tokens and DB credentials regularly

Security Headers

http
  .headers(headers -> headers
    .contentSecurityPolicy(csp -> csp
      .policyDirectives("default-src 'self'"))
    .frameOptions(HeadersConfigurer.FrameOptionsConfig::sameOrigin)
    .xssProtection(Customizer.withDefaults())
    .referrerPolicy(rp -> rp.policy(ReferrerPolicyHeaderWriter.ReferrerPolicy.NO_REFERRER)));

Rate Limiting

• Apply Bucket4j or gateway-level limits on expensive endpoints
• Log and alert on bursts; return 429 with retry hints

Dependency Security

• Run OWASP Dependency Check / Snyk in CI
• Keep Spring Boot and Spring Security on supported versions
• Fail builds on known CVEs

Logging and PII

• Never log secrets, tokens, passwords, or full PAN data
• Redact sensitive fields; use structured JSON logging

File Uploads

• Validate size, content type, and extension
• Store outside web root; scan if required

Checklist Before Release

• Auth tokens validated and expired correctly
• Authorization guards on every sensitive path
• All inputs validated and sanitized
• No string-concatenated SQL
• CSRF posture correct for app type
• Secrets externalized; none committed
• Security headers configured
• Rate limiting on APIs
• Dependencies scanned and up to date
• Logs free of sensitive data

Remember: Deny by default, validate inputs, least privilege, and secure-by-configuration first.