With PHP powering a large portion of all websites globally, it has unfortunately become a prime target for hackers looking to breach sites through code level vulnerabilities. Implementing proper security measures is crucial.
This guide covers key PHP web security risks and provides actionable measures you can take to harden your website against threats.
OWASP Top 10 Security Risks
The OWASP Top 10 report summarizes the most critical web application security flaws. Here is how the top risks apply to PHP:
Injection Attacks
This includes SQL injection, where malicious input is used to access or corrupt databases. Use parameterized queries and input validation to prevent.
Broken Authentication
If account credentials or sessions are not properly secured, unauthorized access can occur. Enable 2FA, limit login attempts, use bcrypt password hashing.
Sensitive Data Exposure
Improper handling of private data like financial info or healthcare records. Encrypt transmission and storage using SSL, AES-256, etc.
XML External Entities Injection
Allows exposing internal files and code. Disable XML entity parsing in PHP and validate all XML inputs.
Broken Access Control
Restrict access to files, directories and functions based on user roles and permissions.
Security Misconfigurations
Lock down access to configuration files, disable unused services, follow hardening guides to prevent system and PHP environment misconfigs.
Cross Site Scripting XSS
Injecting client side code leading to UI redressing or session hijacking. Scrub all outputs before rendering HTML.
Insecure Deserialization
Can allow remote code execution. Only deserialize from trusted sources after vetting.
Using Components with Known Vulnerabilities
Libraries, frameworks and CMS platforms can contain exploitable bugs. Keep WordPress, Drupal, plugins updated.
Insufficient Logging & Monitoring
Attack detection requires proper event logging and monitoring. Implement security event alerting with tools like Fail2ban.
Best Practices for PHP Security
Beyond mitigating OWASP top risks, follow these general best practices:
Validate and Sanitize All Inputs
Scrub all $_GET, $_POST, and $_COOKIE data to prevent XSS and code injection risks.
Use Parameterized Queries
Pass variables to SQL separately from query strings to avoid SQLi.
Hash & Encrypt Sensitive Data
Protect stored passwords, API keys, and personal data.
Avoid Executing Remote Code
Be extremely cautious when allowing eval(), system(), exec() etc.
Implement Role Based Access Control (RBAC)
Only grant permissions required for a particular user role.
Apply Security Patches
Patch PHP itself, web servers, OS, and frameworks regularly.
Install PHP Security Tools
Enable mod_security for Apache. Integrate web application firewalls.
Properly securing PHP web applications takes diligence, but following the recommendations outlined here will go a long way to hardening your websites against threats. Monitor emerging vulnerabilities, keep all software updated, and utilize security tools and best practices to lock down PHP.