Websites are subjected to countless attacks every day. A website vulnerability refers to a weakness or misconfiguration in the code of a website or web application that enables attackers to gain control of the site or even the hosting server. Many of these vulnerabilities are exploited through automated tools, such as botnets.
Cybercriminals create advanced tools that scan the internet for widely used platforms like WordPress or Joomla, targeting known and publicly disclosed vulnerabilities. Once these weaknesses are identified, attackers exploit them to steal sensitive data, distribute malicious content, inject spam, or deface the compromised website. Proactive measures, such as regular updates and vulnerability testing, are essential to safeguarding websites from such threats.
Most Common Website Vulnerabilities
Six common types of website vulnerabilities are frequently exploited by attackers. While this isn’t an exhaustive list, like the OWASP Top 10, of all the potential vulnerabilities a determined attacker may discover in an application, it covers some of the most well-known vulnerabilities found in websites today.
SQL Injections
SQL injection vulnerabilities occur when user input is directly passed to a database without proper validation. Cybercriminals exploit these weaknesses by injecting malicious code, known as payloads, into a website’s database. This allows them to manipulate the database in various ways, such as:
- Inserting malicious or spam content into the site
- Stealing sensitive customer information
- Bypassing authentication to gain complete control of the website
SQL injection is one of the most commonly exploited website vulnerabilities due to its flexibility and effectiveness. It is frequently used to compromise open-source content management systems (CMS) like Joomla!, WordPress, and Drupal. For instance, SQL injection attacks have been linked to breaches such as the U.S. Election Assistance Commission and a popular Grand Theft Auto video game forum, exposing user credentials and sensitive data.
Cross-Site Scripting (XSS) Attacks
Cross-site scripting (XSS) occurs when attackers inject malicious scripts into a website through unsanitized user input or other vulnerable fields. These scripts are then executed in the browsers of website visitors, making the visitors—not the website or server—the primary targets. Typically, attackers use JavaScript to perform malicious actions, as browsers cannot distinguish between legitimate and harmful scripts. This can result in:
- Session hijacking
- Distribution of spam content to unsuspecting users
- Theft of session data
XSS vulnerabilities have been responsible for some of the largest-scale attacks on WordPress, but they are not limited to open-source platforms. For example, a cross-site scripting vulnerability in gaming giant Steam’s system exposed user login credentials to potential attackers. Proactive measures, such as input sanitization and proper encoding, are essential to protecting against XSS attacks.
Command Injection Vulnerabilities
Command injection vulnerabilities enable attackers to remotely pass and execute malicious code on the website’s hosting server. This occurs when user input, such as header information, is invalid, allowing attackers to insert shell commands with the user data. Command injection attacks are hazardous because they can enable attackers to:
- Hijack the entire website
- Take control of the whole hosting server
- Use the hijacked server for botnet attacks
One of the most significant and widespread command injection vulnerabilities was the Shellshock vulnerability, which affected most Linux distributions. Proper input validation and secure coding practices are essential for preventing command injection attacks.
File Inclusion Vulnerabilities (LFI/RFI)
Remote File Inclusion (RFI) attacks include functions in server-side web application languages like PHP to execute code from a remotely stored file. Attackers host malicious files and exploit improperly sanitized user input to inject or alter an included function in the victim site’s PHP code. This inclusion can be used to:
- Deliver malicious payloads that can launch attacks and phishing pages in visitors’ browsers
- Include malicious shell files on publicly accessible websites
- Take control of the website’s admin panel or hosting server
Local File Inclusion (LFI) attacks, similar to RFI, occur when user input can alter the whole or absolute path to included files. Attackers can leverage this vulnerability to gain, read, or modify sensitive local files, such as configuration files containing database credentials. A directory traversal attack can also manipulate the file path to access backend and server files, exposing sensitive data. If an attacker can include log files seeded with malicious code via public interaction, LFI could escalate into an RFI attack.
These vulnerabilities are often used to launch attacks, such as DDoS and cross-site scripting (XSS). They have also been used to steal sensitive financial information, as demonstrated when Starbucks fell victim to an inclusion attack that exposed customer credit card data.
Cross-Site Request Forgery (CSRF)
Cross-site request forgery (CSRF) attacks are less common but can be highly damaging. CSRF attacks trick users or administrators into unknowingly performing malicious actions on behalf of the attacker. As a result, attackers can use valid user input to:
- Change order values and product prices
- Transfer funds between accounts
- Alter user passwords to hijack accounts
These attacks are hazardous for eCommerce and banking websites, where attackers can access sensitive financial information. One notable CSRF attack controlled a Brazilian bank’s DNS settings for over five hours.
Security Misconfigurations
Security issues can arise when security controls and configurations at any website layer—such as the application, web server, network services, platform, framework, or databases—are set up incorrectly. These issues may include:
- Using outdated components (e.g., unused pages, features, unpatched software)
- Leaving unnecessary admin ports open
- Enabling outbound connections to internet services, directory services, and more
Common security misconfigurations include broken authentication, improper access control, misconfigured cloud storage permissions, inadequate encryption settings, and the failure to turn off unnecessary services or features.
Impact of Website Vulnerabilities
Website vulnerabilities pose a significant risk to eCommerce businesses, impacting their reputation and revenue. When exploited, these vulnerabilities can grant unauthorized access to sensitive data, compromising the integrity of the entire site. Personal information captured through a user’s browser can also be used to execute malicious scripts, intensifying cybersecurity threats. Ensuring strong website security is not optional; it is an essential requirement.
Rising Data Breaches: A Growing Threat
In 2023, the global landscape saw a surge in cyberattacks and data breaches, with a staggering 694 breaches reported and over 612.4 million records compromised worldwide. Among the most significant incidents was the MOVEit violation in May 2023, which affected an estimated 17.5 million individuals, exploiting vulnerabilities in Progress MOVEit software. Affected organizations included prominent institutions like Johns Hopkins University and the University of Utah.
These breaches highlight the urgent need for robust security measures, particularly in the education and healthcare sectors, which are prime targets for cybercriminals.
How to Identify and Fix Website Vulnerabilities
There are simple steps you can take to manage and prevent vulnerabilities from allowing hackers to gain unauthorized access to your website and sensitive information.
Keep All Applications Updated
The first essential step in securing your website is ensuring all applications and their associated plugins are up to date. Vendors regularly release critical security patches for their software, so it’s essential to apply these updates promptly. Cybercriminals monitor open-source application news and often exploit known vulnerabilities once update notices are published. Subscribing to automatic updates and email notifications for critical patches will help you stay ahead of potential attackers.
Implement a Web Application Firewall (WAF)
A Web Application Firewall (WAF) is the first line of defense against those probing your website for vulnerabilities. WAFs filter out malicious traffic before it reaches your website, blocking bots, known spam or attack IP addresses, automated scanners, and harmful user input.
Utilize a Malware and Website Vulnerability Scanner
Your last line of defense should include a reputable automated malware scanner. It is essential to choose one that can automatically identify vulnerabilities and remove known malware. You can try our free external website scanner to check for malicious code on your site and ensure it is up-to-date and secure.
For more advanced users, manually reviewing code and implementing PHP filters to sanitize user input is also viable. This includes limiting image uploads to only .jpg or .gif files and allowing form submissions to accept only expected input. However, combining automated and manual security checks offers a more comprehensive approach to cybersecurity.
Web Application Security: A Critical Priority
Understanding the types of vulnerabilities that hackers may exploit is a crucial first step in securing your website. These vulnerabilities can seriously affect your website, server, and customers’ data.
Discover how SiteLock’s website security plans can help protect your site and patch vulnerabilities. If your site has already been compromised, find out how we can assist in fixing hacked websites.
