Brute Force Attack
Last updated: January 16, 2026
Brute force attacks use automated tools to try many password combinations against login forms, APIs, or other authentication endpoints.
Scan for This VulnerabilityWhat is Brute Force Attack?
Attackers use automated tools to rapidly try thousands or millions of password combinations. Without proper protections, they can eventually guess weak passwords. Modern attacks also use credential stuffing - trying username/password pairs leaked from other breaches.
Why It's Dangerous
This vulnerability can allow attackers to access sensitive data, compromise user accounts, or gain unauthorized control over your application. In AI-generated code, this issue is particularly common because security measures are often deprioritized in favor of rapid feature development.
Why AI Code Is Vulnerable
AI code generation tools focus on producing functional code quickly. They often generate patterns that work correctly but lack the defensive measures experienced security engineers would implement. This makes brute force attack particularly prevalent in vibe-coded applications.
Understanding the Technical Details
Brute Force Attack is classified as a high-severity vulnerability because of its potential to cause significant damage to your application and users. Understanding the technical mechanics helps you recognize and prevent this issue in your own code.
This vulnerability typically occurs when security controls are either missing entirely, improperly configured, or incorrectly implemented. In many cases, the code appears to work correctly during development and testing, but the security flaw becomes exploitable once the application is deployed and accessible to malicious actors.
Attackers actively scan for this type of vulnerability using automated tools. Once discovered, exploitation can be rapid—often within hours of your application going live. The consequences range from data theft and account takeover to complete system compromise depending on the application's architecture.
For vibe-coded applications built with platforms like Lovable, Bolt.new, Replit, or v0.dev, this vulnerability appears in roughly 20-40% of deployments according to security research. The AI-generated patterns often follow insecure defaults that require manual security hardening.
How It Happens
- No rate limiting on authentication
- No account lockout mechanism
- Weak password requirements
- No CAPTCHA or challenge
- Detailed error messages enabling enumeration
Impact
Account compromise
Unauthorized access to data
Service disruption from attack volume
Reputational damage
How to Detect
- Monitor for high-volume login attempts
- Check for rate limiting on auth endpoints
- Look for account lockout mechanisms
- Test password complexity requirements
How to Fix
Implement rate limiting
Limit authentication attempts per IP and account.
// Using upstash ratelimit
import { Ratelimit } from '@upstash/ratelimit';
const ratelimit = new Ratelimit({
limiter: Ratelimit.slidingWindow(5, '1 m'), // 5 attempts per minute
});
const { success } = await ratelimit.limit(ip + ':' + email);
if (!success) {
return res.status(429).json({ error: 'Too many attempts' });
}Add progressive delays
Increase delay after failed attempts.
// Progressive delay
const delays = [0, 1000, 2000, 5000, 10000, 30000];
const delay = delays[Math.min(failedAttempts, delays.length - 1)];
await new Promise(r => setTimeout(r, delay));Use auth provider protections
Leverage built-in brute force protection.
// Supabase has built-in rate limiting
// Configure in dashboard: Authentication > Rate Limits
// Firebase has similar protections
// Enable in Firebase Console > Authentication > Sign-in methodCommonly Affected Platforms
Prevention Best Practices
The most effective approach to brute force attack is prevention. Implementing security measures during development is significantly easier and less costly than remediating vulnerabilities after deployment.
Security-First Development
When using AI code generation tools, always review the generated code for security implications. AI tools prioritize functionality over security, so treat all generated code as requiring security review. Establish a checklist of security requirements specific to your application type and verify each before deployment.
Continuous Security Testing
Integrate security scanning into your development workflow. Run scans after major code changes, before deployments, and on a regular schedule for production applications. Early detection of vulnerabilities reduces remediation costs and prevents potential breaches.
Defense in Depth
Never rely on a single security control. Implement multiple layers of protection so that if one control fails, others still protect your application. For example, combine authentication, authorization, input validation, and output encoding to create comprehensive protection against attacks.
Stay Informed
Security threats evolve constantly. Follow security researchers, subscribe to vulnerability databases, and monitor your dependencies for known issues. Understanding emerging threats helps you proactively protect your applications before attackers exploit new techniques.
Is Your App Vulnerable?
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Get Starter ScanFrequently Asked Questions
What's the difference between brute force and credential stuffing?
Brute force tries many passwords for one account. Credential stuffing tries leaked username/password pairs from other breaches across many accounts. Both need rate limiting, but credential stuffing also needs breach monitoring and encouraging unique passwords.
Should I lock accounts after failed attempts?
Yes, but carefully. Temporary lockouts (15-30 min) prevent brute force without permanent denial of service. Notify users of lockouts via email. Consider CAPTCHA challenges instead of hard lockouts to avoid attackers locking out legitimate users.