As web applications continue to power a vast array of services and business operations, they have become prime targets for cybercriminals seeking to exploit vulnerabilities. Developers play a critical role in ensuring that these applications remain secure and resilient against evolving threats. Understanding the most common and critical vulnerabilities. such as SQL Injection, Cross-Site Scripting (XSS), and Cross-Site Request Forgery (CSRF) is essential for building secure applications. This blog aims to raise awareness among developers about these threats and provide actionable mitigation strategies to help protect web applications from malicious attacks.
CROSS-SITE SCRIPTING:
Cross-site scripting – also known as XSS, will allow the attacker to inject malicious scripts into the trusted website to obtain sensitive information like session cookies and redirect users to a malicious site. There are different types of XSS used, like Stored XSS, Reflected XSS, and DOM-based XSS.
Stored XSS aka Persistent XSS:
It stores the malicious scripts on the database, command section, or user profile of the webserver permanently. whenever the affected page loads, a malicious script executes on the victim’s browser.
Reflected XSS aka Non-Persistent XSS:
Unlike stored XSS where the attacker injects malicious code into a web application and the code reflects immediately on the user’s browser, Reflected XSS requires the attacker to craft malicious URLs and share them with the victim. If the victim clicks the URL malicious script will be executed in the victim’s browser.
DOM-Based XSS:
DOM based XSS works on the client browser rather than server. Attackers inject malicious script into the DOM (Document Object Model) of the webpage and executed by the users browser. The script does not involve server-side reflection or storage as it operates entirely with client-side JavaScript.
Impact of XSS
- Attackers can gain sensitive data such as session cookies, authentication tokens, and personal data like user credentials and payment details.
- The attacker can manipulate settings, delete data, or lock legitimate users out of the system.
- Stored XSS can execute scripts that crash browsers or consume more resources it can cause a denial of service for legitimate users.
Mitigation strategies for XSS:
- Ensure that all user inputs are validated and sanitised before being accepted. This prevents malicious scripts from being included in inputs.
- Encode data to prevent it from being interpreted as executable code by the browser.
Implement CSP (content security policy) to restrict the types of content that can be executed on the webpage, reducing the chances of malicious scripts being executed.
CROSS-SITE REQUEST FORGERY(CSRF)
One kind of confused deputy cyberattack is a cross-site request forgery attack, which deceives a user into mistakenly entering their login credentials to initiate a state-changing action, like transferring money from their account, altering their email address and password, or performing another undesirable action.
Impact of CSRF:
Attackers can change account settings, such as email addresses, phone numbers, and passwords.
Mitigation strategies for CSRF:
- Implement unique tokens in forms that the server verifies with every request.
- Check that the request is coming from the expected source.
Need to enable re-authentication for critical actions like money transfers or account changes.
SQL INJECTION
SQL Injection (SQLi) is a type of cyberattack that targets vulnerabilities in web applications that interact with databases. It occurs when an attacker manipulates SQL queries by injecting malicious SQL code into user input fields.
Impact of SQL Injection:
- An attacker can modify or delete data. leading to corruption, loss, or theft of critical information.
- Attackers can bypass authentication mechanisms by manipulating SQL queries to always return valid user data.
- In some cases, attackers can execute system-level commands on the server through the SQL query, leading to full server compromise.
Mitigation Strategies for SQL Injection:
- The implementation of validation and sanitization of user input is required.
- Need to use stored procedures to encapsulate SQL logic within the database, using parameters for user inputs, reducing the risk of SQL injection.
- Restrict database access to only the necessary permissions, reducing the impact of any successful SQL injection attacks.
CONCLUSION:
In an era where web applications are integral to business operations, understanding and addressing critical vulnerabilities is crucial for developers. SQL Injection, XSS, CSRF, and other common threats can have severe consequences if left unchecked. By familiarizing themselves with these vulnerabilities and incorporating effective mitigation strategies, developers can safeguard their applications and prevent costly security breaches. Security should be an ongoing priority throughout the development lifecycle, and with the right knowledge and tools, developers can contribute to a safer digital environment. Awareness and proactive security measures are the keys to building robust, secure web applications that can withstand the evolving threat landscape.