Common Web Application Vulnerabilities Explained: Understanding the Threats

 

In an increasingly interconnected digital landscape, web applications play a key role in daily activities, facilitating seamless interactions and transactions. From online shopping to social networking, these applications have revolutionized how we engage with technology. However, this surge in digital connectivity has also brought to the forefront a critical issue: web application security vulnerabilities. Web applications are common targets for hackers because they enable easy access to a larger audience, allowing malicious code to spread faster. However, with great convenience comes great responsibility, and the security of web applications has become a paramount concern.

Web application security vulnerabilities are weaknesses in the system that lead to security risks such as hacker attacks or data leaks. According to Statista, over six million data records were exposed globally due to data breaches in the first quarter of 2023. The most exposed data records were found in the fourth quarter of 2020, with about 125 million data sets since the first quarter of 2020. That's why it's essential to regularly test an application's security and use web application vulnerability scanning tools to identify vulnerabilities before they become significant issues.

Common Types of Web Application Security Vulnerabilities

Organizations must safeguard against these common web application vulnerabilities to ensure data security and privacy.

SQL Injection

Structured Query Language (SQL) is extensively utilized in numerous applications to manage database connectivity. SQL vulnerabilities enable attackers to input malicious commands into databases to exfiltrate, change, or delete data. SQL injection attacks target servers that store sensitive data utilized by web applications or services. They become vulnerable when exposed to sensitive information like user credentials and personal data. Using inappropriate user inputs is the most frequent vulnerability that allows for SQL injection attacks.

Impact of SQL injection on applications:

• Attackers can get credentials via SQL injection and then impersonate users and use their authorization rights.
• Attackers can obtain access to sensitive data on servers and alter or add new data to the accessed database.
• Attackers can delete database records or drop entire tables.
• Attackers with operating system privileges can get access to database servers and utilize these privileges to gain access to other confidential systems.

Mitigate the SQL injection attacks by using:

• Parameterized statements or prepared statements to separate user input from SQL code.
• Sanitized user inputs that are safe for database use.
• Web application vulnerability scanning tools to identify potential SQL injection vulnerabilities.

Cross-Site Scripting (XSS)

Like SQL injection attacks, XSS attacks involve inserting malicious scripts into websites or web applications. The difference is that the malicious code is only executed in the browser when the user visits a hacked website or app. XSS attacks are frequently carried out by injecting code into input fields that the target page executes when users view the page.

Types of XSS Attacks:

• Stored XSS: Attackers inject malicious scripts permanently stored on a target server. When other users access the compromised page, the script executes, affecting all subsequent visitors. 
• Reflected XSS: Malicious scripts are embedded in URLs or input fields, and the server reflects them in the page's response. The script executes when the user interacts with the manipulated URL or input.
• DOM-based XSS: The attack modifies the DOM (domain object model) on the client side (the browser). In this case, the HTTP response on the server side is unchanged; instead, the client code executes unexpectedly due to a malicious change to the DOM environment.

These steps will help you prevent XSS attacks:

• Validate and sanitize user inputs to prevent the injection of malicious code.
• Encode user-generated content before displaying it to prevent the execution of injected scripts.
• Implement a Content Security Policy (CSP) to specify which content sources are considered legitimate, preventing the execution of scripts from untrusted sources.

Cross-Site Request Forgery (CSRF)

It is an attack where an attacker forces a victim to execute unintended actions within a web application. Exploiting the trust between the user, browser, and application, the attacker deceives the victim into submitting a request that triggers malicious actions on the web app. The motives behind CSRF attacks can vary, ranging from mischievous pranks to facilitating unauthorized financial transactions.

How CSRF attacks work:

• The attacker crafts a malicious request and convinces the user to interact with it, often through a manipulated link or image.
• The user's browser sends the request, including their session cookies, to the target application.
• The application receives the request and acts on the user's behalf without verifying the source's legitimacy.

Countermeasures to prevent CSRF vulnerabilities:

• Anti-CSRF Tokens: Generate and validate unique tokens for each user session to ensure requests originate from the legitimate user.
• SameSite Cookie Attribute: Set the SameSite attribute on cookies to restrict usage to the same origin, mitigating CSRF attacks.
• Referer Header Validation: Check the Referer header to verify the source of incoming requests.

Insecure Deserialization

A web application vulnerability occurs when an application processes untrusted data from an external source, such as user input, without proper validation. Attackers exploit this vulnerability to manipulate serialized data, potentially leading to remote code execution, data exposure, and other malicious activities.

Insecure deserialization poses the following risks:

• Remote Code Execution: By manipulating serialized objects, attackers can execute any code on the server.
• Data Exposure: Insecure deserialization can expose sensitive data saved in serialized objects.
• Denial of Service: Attackers can create malicious serialized data that cause resource exhaustion or system crashes.

Insecure deserialization vulnerabilities can be prevented in the following ways:

• Validate and sanitize serialized data to adhere to expected formats and structures.
• Use trusted and secure serialization libraries that enforce strict deserialization rules.
• Implement a digital signature to verify data integrity; however, this only works if tests are performed before the deserialization process begins.

Broken Authentication and Session Management

These vulnerabilities occur when inadequate security measures allow attackers to compromise user authentication or hijack active user sessions, potentially gaining unauthorized access to sensitive information and functionalities.

The following lists the scenarios that can cause broken authentication:

• Weak passwords and usernames.
• Fixation attacks throughout sessions.
• Customer identity information is not secured when stored.
• Consumer identification data is sent through links that are not encrypted.

Ways of preventing broken authentication attacks:

• Multi-Factor Authentication (MFA): Integrate MFA to increase security, requiring users to provide multiple verification forms.
• Session Handling: Use secure session management techniques, including regular session timeouts and secure session ID generation.
• Password Policies: Enforce strong password policies, such as complexity requirements and regular password changes.

Strengthen Your Applications with HCL AppScan for Vulnerability Management

With HCL AppScan, developers, DevOps teams, and security professionals gain access to a comprehensive suite of technologies to identify application security vulnerabilities throughout the software development lifecycle. Protect the business and customers by utilizing best-in-class testing tools, centralized visibility and oversight, and flexible deployment options such as on-premises, on-cloud, and cloud-native. 

As one of the web application vulnerability scanning tools, HCL AppScan can fortify applications, ensuring robust security measures and providing peace of mind for your organization and those who rely on your software solutions.