Drupal Security Audit: Complete Vulnerability Assessment and Protection

Recently, on one project, we discovered that a missed update of the Views module allowed an attacker to access the admin panel through the SA-CORE vulnerability. It cost the client two weeks of downtime and serious reputational damage. On average, lack of regular security audits costs Drupal sites 150,000 to 300,000 rubles due to downtime and recovery. A Drupal security audit prevents such scenarios: we check core configuration, modules, user roles, and custom code to identify gaps before attackers find them.

We conduct full-scope audits—from scanning via drush pm:security to PHP code analysis for XSS and SQL injection. The result is a detailed report with priorities and ready patches.

Common Drupal Vulnerabilities

Outdated Modules and Core

The Drupal Security Team releases regular updates, but many sites lag behind. For example, the Views module received a critical update, but approximately 40% of sites did not apply it in time (data from Drupal Security Advisories). We check all installed packages via composer audit and drush pm:security. In 90% of audits, we find at least 2-3 modules requiring updates.

Incorrect Access Permissions

The settings.php file should be read-only (444), and the files directory should not contain PHP files. Statistics: in 30% of audits, we find at least one file with permissions 644 or 755, which opens access to configuration.

Trusted Host Patterns are a critical setting: without them, the site is vulnerable to Host header injection. We always enable it. According to our data, 60% of sites lack this setting.

How to Protect Against SQL Injection in Custom Modules

All database queries must use parameterized queries. Consider this example:

// Unsafe (do not do this):
$result = \Drupal::database()->query("SELECT * FROM node WHERE title = '" . $input . "'");

// Correct:
$result = \Drupal::database()->query(
    "SELECT * FROM node WHERE title = :title",
    [':title' => $input]
);

We also check the use of Xss::filter() for output in Twig templates. In 70% of cases, we find at least one SQL injection in custom modules.

What Are Recommended Audit Frequencies?

We recommend conducting an audit at least once a year, and after every major core or module update. For high-security sites, every six months is advisable. This helps detect vulnerabilities early and reduces the risk of a breach by 80%.

Audit Process

1. Configuration analysis — checking settings.php, .htaccess, service files.
2. Vulnerability scanning — drush pm:security, composer audit, Security Review.
3. Code review — searching for XSS, SQL injection, CSRF, unsafe file operations.
4. Report — list of vulnerabilities by severity, recommendations, ready patches.
5. Remediation (optional) — our engineers fix the identified issues.

Timeline and What's Included

The audit takes 1 to 3 days depending on site size. The report includes:

We also provide:

• A detailed report with priorities (critical, high, medium, low).
• Fixed configuration files (if remediation is ordered).
• Consultation on further protection.

Why Manual Audit is More Effective than Automated?

Automated scanners provide quick results but often miss business logic vulnerabilities and custom code errors. A manual audit by an experienced engineer detects up to 99% of vulnerabilities, including those related to architectural decisions. Additionally, manual audits produce minimal false positives, saving time on result verification.

Based on our data from 50 projects, manual audits uncover 5 times more critical vulnerabilities than automated scans. The savings from preventing a breach can reach 500,000 rubles, far exceeding the audit cost.

Common Drupal Configuration Mistakes

We most frequently find:

• Missing Trusted Host Patterns (60% of sites);
• Incorrect file permissions (30%);
• Outdated modules (40%);
• SQL injection in custom code (70%).

All these issues are resolved within the audit. We also configure the Security Review module, which automatically checks critical parameters: file permissions, role permissions, PHP settings, input filters, and private files. Private files must be stored outside the web root—a standard recommendation that many ignore.

Conclusion

A Drupal security audit is not a one-time action but a regular practice that protects your project from serious financial losses. With 7 years of Drupal experience and over 30 completed projects, we have contributed to fixing vulnerabilities for the Drupal Security Team and know how to secure your site at the core level. Contact us for a free project assessment and get a detailed action plan to protect your Drupal site.

Web Application Security: HTTPS, CSP, XSS, CSRF, WAF, DDoS Protection

A website breach rarely looks like in movies. More often it's: a bot finds an unprotected /admin/export endpoint, downloads the customer database, and closes the connection. Or: through an outdated WordPress plugin, a web shell is uploaded, and the server starts sending spam. Or quieter: an XSS in a comment field allows stealing admin session cookies, unnoticed for months. We have analyzed dozens of such cases — each vulnerability could have been fixed at the development or audit stage.

Web application security is not a single setting. It's layers of protection, each closing a separate class of attacks. Order an audit — we'll assess the project and deliver a turnkey plan within 2–4 weeks.

How do we ensure comprehensive web application security?

HTTPS and Proper TLS Configuration

HTTPS is the minimum mandatory level. But having an SSL certificate and having a properly configured TLS are different things.

In Nginx/Apache configuration we check:

• Protocols: only TLS 1.2 and TLS 1.3, SSLv3 and TLS 1.0/1.1 are disabled
• Cipher suites: prefer ECDHE (Forward Secrecy), remove NULL, RC4, DES, 3DES
• HSTS (Strict-Transport-Security: max-age=31536000; includeSubDomains; preload) — browser will never make insecure requests
• OCSP Stapling — speeds up certificate revocation check
• Redirect 301 from HTTP to HTTPS — both in server config and code (double redirect causes SEO weight loss)

Check: SSL Labs (ssllabs.com/ssltest) should show A or A+. If B, the configuration is weak.

Let's Encrypt + Certbot for production is standard. Automatic renewal via certbot renew in cron. Wildcard certificates for subdomains via DNS-01 challenge.

Content Security Policy: The Most Powerful and Complex Protection

CSP is an HTTP header that tells the browser which sources are allowed to load resources. A properly configured CSP completely blocks most XSS attacks, even if the vulnerability exists in the code.

The problem: breaking the site with an incorrect CSP is easy. default-src 'none' — and fonts, images, JS stop working. So we start with Content-Security-Policy-Report-Only — CSP logs violations but does not block anything. We monitor reports for 2–4 weeks, refine the policy, then switch to enforcement mode.

Example of a real policy for a site with Google Analytics, Google Fonts, and Stripe:

Content-Security-Policy:
  default-src 'self';
  script-src 'self' https://www.googletagmanager.com https://js.stripe.com 'nonce-{random}';
  style-src 'self' https://fonts.googleapis.com 'unsafe-inline';
  font-src 'self' https://fonts.gstatic.com;
  frame-src https://js.stripe.com;
  img-src 'self' data: https://www.google-analytics.com;
  connect-src 'self' https://api.stripe.com https://www.google-analytics.com;
  report-uri /csp-report;

nonce — a random string generated server-side per request. Inline scripts with the correct nonce are allowed; without nonce, they are blocked. This completely breaks XSS via <script>alert(1)</script>.

'unsafe-inline' in style-src is a compromise for inline styles. It's better to remove it by moving all styles to CSS files, but that requires refactoring.

Why XSS Remains the Most Common Vulnerability?

XSS (Cross-Site Scripting) — injection of JS code through user input. According to OWASP, XSS is in the top 3 web application vulnerabilities. Three types:

Protection: never insert user input into HTML without escaping. In PHP — htmlspecialchars() with ENT_QUOTES. In Laravel Blade templates — {{ $var }} is safe, {!! $var !!} is dangerous. In React — {variable} is safe, dangerouslySetInnerHTML is dangerous. For Rich Text — use htmlpurifier on PHP or DOMPurify in the browser.

CSRF: Protecting Forms and APIs

CSRF (Cross-Site Request Forgery) — an attacker forces the victim's browser to send a request on their behalf. Example: a user is logged into a bank, opens a malicious page, which makes fetch('https://bank.ru/transfer?to=evil&amount=50000') — if the bank is unprotected, money is transferred.

CSRF tokens — standard protection for forms: the server generates a random token, stores it in the session, and inserts it as a hidden field in the form. On POST request, the token is verified. The attacker does not know the token. Laravel does this automatically with @csrf.

SameSite cookies — modern protection: SameSite=Strict or SameSite=Lax prevents the browser from sending cookies in cross-site requests. Works in all modern browsers.

API without sessions (JWT, Bearer tokens) — CSRF is irrelevant if the token is not stored in a cookie (but in the Authorization header or localStorage). However, localStorage is vulnerable to XSS — so for sensitive data, HttpOnly cookies with SameSite are preferable.

WAF and DDoS Protection

WAF (Web Application Firewall) filters HTTP traffic for attacks: SQL injection, XSS, path traversal, known exploit patterns. Options:

• Cloudflare WAF — cloud-based, OWASP Top 10 rules out of the box, custom rules via expressions. Managed Rules automatically block new threats.
• ModSecurity (Nginx/Apache) — self-hosted, OWASP Core Rule Set (CRS). Flexible but requires tuning and monitoring of false positives.
• AWS WAF — for infrastructure on AWS, integrates with CloudFront and ALB.

DDoS protection. Cloudflare at L3/L4/L7 is the de facto standard for most sites. Automatic mitigation of volumetric attacks, Under Attack Mode during active attacks. For critical infrastructure — Cloudflare Magic Transit or specialized solutions (Qrator, StormWall for the Russian market).

Rate Limiting at the application level — an additional layer. Laravel ThrottleRequests middleware: 60 requests per minute per IP for general endpoints, 5 for /login and /password/reset. Redis as a counter store — mandatory for horizontally scalable systems (otherwise limits are not synchronized between servers).

Other Mandatory Measures

Security headers. Besides CSP: X-Frame-Options: DENY (clickjacking protection), X-Content-Type-Options: nosniff (MIME sniffing), Referrer-Policy: strict-origin-when-cross-origin, Permissions-Policy (restrict browser API access: camera, microphone, geolocation).

SQL injection. Prepared statements everywhere. No concatenation of user input into SQL strings. ORM (Eloquent, Doctrine) protects by default. $wpdb->prepare() in WordPress is mandatory.

Dependency updates. composer audit and npm audit in CI/CD pipeline. Dependabot or Renovate for automatic PRs with updates. Critical CVEs — patch within 24 hours.

Secrets and configuration. .env — never in Git. Secrets in production — via CI/CD environment variables (GitHub Secrets, GitLab CI Variables) or HashiCorp Vault. Leak detection: git-secrets, truffleHog in pre-commit hooks.

How We Work

1. Audit — code scanning, configuration review, dependency analysis, manual business logic verification.
2. Planning — vulnerability remediation plan, stack selection (CSP, WAF, rate limiting).
3. Implementation — TLS setup, CSP configuration, headers, Rate Limiting, WAF.
4. Testing — re-penetration test, load testing, false positive check.
5. Deployment and Monitoring — enable production CSP, set up alerts, train the team.

What's Included

• Report with found vulnerabilities and recommendations (PDF + code snippets)
• Ready TLS configuration (Nginx/Apache)
• CSP policy with Report-Only and production versions
• WAF and Rate Limiting setup
• Dependency update plan
• Access to monitoring tools (Sentry, Datadog)
• 30 days of post-audit support (consultations, fixes)

Timeline and Cost

The budget is calculated individually — contact us for a project evaluation.