Common Website Security Issues (and How to Prevent Them)

Website security continues to be a critical concern for Australian businesses of all sizes. According to the Australian Cyber Security Centre’s 2024 Annual Cyber Threat Report, cybercrime reports increased significantly, with cyber attacks becoming increasingly sophisticated and frequent. Even minor vulnerabilities can result in significant financial losses, reputational damage, and regulatory penalties.

Your website serves as more than your digital storefront; it’s a vital business asset that handles sensitive customer data, facilitates transactions, and represents your brand to the world. For organisations seeking to build or maintain robust web applications, understanding common security vulnerabilities isn’t optional; it’s fundamental to protecting your business interests and maintaining customer trust.

Here are the most prevalent website security vulnerabilities we encounter when auditing client systems in Australia, along with enterprise-grade solutions to address them:

1. Content Management System and Plugin Vulnerabilities

The Risk: Popular content management systems like WordPress, Joomla, and Drupal power millions of websites globally, making them attractive targets for automated attacks. Whilst their extensibility through plugins and themes offers tremendous functionality, it also introduces significant security considerations. Third-party plugins, particularly those that are poorly maintained, inadequately coded, or no longer supported, create attack vectors that malicious actors actively exploit.

Outdated CMS core installations, themes, or plugins are systematically scanned by automated bots seeking known vulnerabilities. When organisations rely heavily on plugin-based solutions without proper vetting, they’re essentially trusting their security to unknown third parties with varying levels of security expertise.

Prevention Strategies:

• Conduct thorough due diligence on all plugins before implementation: examine developer reputation, update frequency, security track record, and community support
• Implement a plugin governance policy that limits installations to essential, well-maintained components from trusted sources
• Establish regular audit schedules to identify and remove unused or abandoned plugins immediately
• Harden your CMS through security best practices: disable unnecessary features, implement strict file permissions, restrict access to sensitive configuration files (wp-config.php, .htaccess, etc.)
• Consider custom development over plugin proliferation when building mission-critical functionality. This approach provides better security control and reduces third-party dependencies
• Implement automated vulnerability scanning as part of your continuous integration pipeline

Code Brewery Perspective: When we build client websites, we prioritise custom development and minimise plugin dependencies. This approach allows us to maintain tight security control whilst delivering the exact functionality your business requires, without the overhead of unnecessary third-party code.

2. Authentication Weaknesses and Credential Management

The Risk: Inadequate authentication mechanisms remain one of the most common entry points for breaches. Credential stuffing attacks (which leverage previously compromised username and password combinations from other breaches) and brute-force attacks targeting login interfaces pose constant threats to web applications. The OWASP Top 10 identifies identification and authentication failures as a critical security risk affecting web applications globally.

Weak password policies, lack of multi-factor authentication, and insufficient account lockout mechanisms create opportunities for unauthorised access. Once attackers gain entry through compromised credentials, they can access sensitive data, inject malicious code, or pivot to other systems within your infrastructure.

Prevention Strategies:

• Implement comprehensive password policies that prioritise length over complexity: encourage passphrases (e.g., “Sydney-Harbour-Bridge-2025-Architecture”) rather than short, complex passwords that users struggle to remember and often reuse
• Deploy multi-factor authentication (MFA) for all administrative access and consider implementing it for customer-facing applications handling sensitive data
• Implement intelligent rate limiting and progressive delays on failed login attempts to mitigate brute-force attacks
• Establish automated monitoring for suspicious authentication patterns, including unusual geographical locations, rapid-fire login attempts, or access from known malicious IP ranges
• Enforce regular password rotation policies, particularly during staff transitions or following security incidents
• Consider implementing single sign-on (SSO) solutions for enterprise applications to centralise authentication and improve security oversight
• Maintain detailed authentication logs for security auditing and forensic analysis

3. SQL Injection Vulnerabilities

The Risk: SQL injection attacks exploit insufficient input validation in web applications, allowing attackers to manipulate database queries through user-supplied data. Despite being well-known for over two decades, injection attacks remain in the OWASP Top 10 due to their prevalence and potential impact. When applications fail to properly sanitise inputs from forms, search fields, or URL parameters, attackers can inject malicious SQL commands that may expose, modify, or delete database contents.

This vulnerability can lead to unauthorised data access, authentication bypasses, and complete database compromise. Despite being well-documented, SQL injection remains prevalent due to poor coding practices and inadequate security awareness during development.

Prevention Strategies:

• Implement parameterised queries (prepared statements) across all database interactions. This separates SQL code from data, preventing injection attacks
• Apply strict input validation and sanitisation on all user-supplied data before processing
• Employ stored procedures with appropriate permissions to limit direct database access from application code
• Implement the principle of least privilege for database accounts; applications should operate with minimal necessary permissions
• Conduct regular code reviews with security-focused engineers who understand OWASP Top 10 vulnerabilities
• Deploy web application firewalls (WAF) to provide an additional layer of defence against injection attacks
• Maintain comprehensive error handling that doesn’t expose database structure or query details to end users

Code Brewery Perspective: Our development team follows secure coding standards from project inception. We implement prepared statements as standard practice, conduct security-focused code reviews, and maintain comprehensive testing protocols that include SQL injection vulnerability assessments.

4. Cross-Site Scripting (XSS) Exploits

The Risk: Cross-Site Scripting vulnerabilities occur when applications include untrusted data in web pages without proper validation or escaping. Listed as a critical injection vulnerability by OWASP, XSS attacks enable malicious actors to inject scripts that execute in users’ browsers, potentially stealing session tokens, credentials, or sensitive information. XSS attacks can also deface websites or redirect users to malicious sites.

These vulnerabilities are particularly concerning for applications with user-generated content, such as forums, comment sections, or any interface accepting text input from users.

Prevention Strategies:

• Implement context-sensitive output encoding for all user-supplied data before rendering in HTML, JavaScript, CSS, or URL contexts
• Deploy Content Security Policy (CSP) headers to restrict which sources can execute scripts on your pages
• Validate and sanitise all input on both client and server sides; never trust client-side validation alone
• Use modern frameworks with built-in XSS protection mechanisms and keep them updated
• Implement HTTP-only cookies for session management to prevent JavaScript access to authentication tokens
• Establish security headers including X-XSS-Protection, X-Content-Type-Options, and X-Frame-Options
• Conduct regular security testing including both automated scanning and manual penetration testing

5. Insecure Data Transmission

The Risk: Transmitting data over unencrypted HTTP connections exposes sensitive information to interception through man-in-the-middle attacks. This vulnerability is particularly concerning on public networks where attackers can easily intercept communications. Beyond security implications, modern browsers actively warn users about non-HTTPS sites, damaging credibility and potentially affecting search engine rankings.

Prevention Strategies:

• Implement TLS/SSL certificates across your entire website; modern standards recommend TLS 1.2 or higher (with TLS 1.3 being preferred for enhanced security)
• Configure automatic HTTPS redirection to ensure all traffic uses encrypted connections
• Implement HTTP Strict Transport Security (HSTS) headers to prevent protocol downgrade attacks
• Establish automated certificate renewal processes to prevent expiry-related outages; most certificates now require renewal every 90 days
• Monitor certificate validity and implement alerting for upcoming expirations
• Consider implementing certificate pinning for mobile applications to prevent certificate-based attacks
• Regularly audit your SSL/TLS configuration using tools like SSL Labs to identify potential weaknesses

6. File Upload Security Gaps

The Risk: Unrestricted file upload functionality represents a critical vulnerability that attackers frequently exploit to upload malicious files, including web shells, malware, or executables. Once uploaded, these files can provide attackers with remote code execution capabilities, enabling them to compromise your entire server infrastructure.

Prevention Strategies:

• Implement comprehensive file type validation using both extension checking and content analysis (MIME type verification)
• Establish strict file size limitations and implement rate limiting to prevent resource exhaustion attacks
• Store uploaded files outside the web root directory and serve them through a controller that enforces access controls
• Implement automated virus and malware scanning for all uploaded files before they’re processed or stored
• Generate unique, unpredictable filenames (using UUIDs or cryptographic hashes) to prevent filename-based attacks
• Configure your web server to prevent execution of scripts within upload directories
• Implement file quarantine procedures where uploads are temporarily isolated until validation completes
• Consider implementing CDN-based upload handling for additional security layers

7. Access Control and Permission Misconfigurations

The Risk: Inadequate access controls and overly permissive user roles increase the risk of both accidental and malicious actions. When users possess more privileges than necessary for their roles, the potential impact of compromised credentials or insider threats escalates significantly.

Prevention Strategies:

• Implement role-based access control (RBAC) with clearly defined permissions for each role
• Follow the principle of least privilege; grant users minimum access required to perform their functions
• Conduct quarterly access reviews to identify and remove unnecessary permissions
• Implement automated user deprovisioning workflows for staff departures
• Establish segregation of duties for critical operations requiring multiple approvals
• Maintain comprehensive audit logs of all privileged actions for security monitoring and compliance
• Implement just-in-time access provisioning for temporary elevated privileges
• Deploy privileged access management (PAM) solutions for administrative accounts

Building a Security-First Culture

Website security isn’t a one-time implementation; it’s an ongoing commitment requiring continuous attention, monitoring, and adaptation. As threat landscapes evolve, your security posture must evolve with them. Organisations that view security as an afterthought rather than a fundamental requirement often find themselves responding to breaches rather than preventing them.

Effective website security requires a multi-layered approach combining technical controls, security-aware development practices, regular testing, and continuous monitoring. It demands investment not only in technology but also in expertise and processes that maintain security standards throughout your application lifecycle.

Frequently Asked Questions About Website Security

What is the most common website security vulnerability?

According to OWASP’s latest research, injection attacks (including SQL injection) and authentication failures remain the most prevalent vulnerabilities. However, misconfigured security settings and outdated CMS platforms with vulnerable plugins are increasingly common attack vectors we see in Australian businesses.

How often should I update my website’s security measures?

Website security requires continuous attention. At minimum, you should: update CMS and plugins monthly (or enable automatic updates), review access permissions quarterly, conduct security audits annually, and monitor for threats continuously. Critical security patches should be applied immediately upon release.

Do small businesses need the same level of website security as large enterprises?

Yes. Cyber criminals often target small businesses specifically because they typically have weaker security defences. The Australian Cyber Security Centre reports that small and medium businesses are increasingly targeted. Whilst the scale may differ, the fundamental security principles apply to organisations of all sizes.

What’s the average cost of a website security breach?

The cost varies significantly based on the breach’s severity, but impacts include direct remediation costs, regulatory fines, legal expenses, and lost business. More importantly, reputational damage can affect customer trust for years. Prevention is substantially more cost-effective than responding to a breach.

Can I handle website security myself, or should I hire professionals?

Basic security measures (strong passwords, regular updates, HTTPS) can be managed in-house. However, comprehensive security including code review, penetration testing, and security architecture requires specialised expertise. Most organisations benefit from partnering with security-focused developers who stay current with evolving threats.

Partner with Security-Focused Developers

At Code Brewery, security is embedded in our development methodology from project inception through deployment and ongoing maintenance. Our Sydney-based team brings deep expertise in secure coding practices, infrastructure hardening, and security testing to every engagement.

Whether you’re building a new web application, modernising legacy systems, implementing custom business software, or seeking an independent security assessment of your current infrastructure, we provide comprehensive solutions tailored to your risk profile and business requirements.

Our website security services include:

• Security-focused web application development using modern frameworks and best practices
• Comprehensive security audits identifying vulnerabilities and providing actionable remediation roadmaps
• WordPress security hardening and custom plugin development
• Infrastructure security configuration and management
• Ongoing security monitoring and maintenance services
• Staff security awareness training tailored to your organisation

Don’t wait for a security incident to prioritise protection. Contact Code Brewery today for a confidential discussion about strengthening your web security posture. We’ll provide a clear, practical assessment of your current state and develop a roadmap to enterprise-grade security that protects your business whilst enabling growth.