React & Angular Security Series #1
Tags: security, sql, programming, javascript
Published: 2023-06-03 22:23:57

## Common Vulnerabilities in React & Angular Applications

React and Angular are two of the most popular JavaScript frameworks for building web applications. They are both open source and have large communities of developers. However, like any software, they are not immune to security vulnerabilities.

This blog post will discuss some of the most common vulnerabilities that can occur in React and Angular applications. It will also provide examples of major events where these vulnerabilities have been exploited.

**Server-side rendering**
Server-side rendering (SSR) is a technique for rendering web pages on the server-side. This means that the HTML, CSS, and JavaScript for a web page is generated on the server and then sent to the client-side.

SSR has a number of security benefits, including:

Improved security: SSR can help to mitigate XSS attacks by preventing malicious code from being injected into the HTML of a web page.
Improved performance: SSR can improve the performance of a web application by reducing the amount of work that needs to be done on the client-side.
Improved SEO: SSR can improve the SEO of a web application by making it easier for search engines to index the content of a web page.
However, SSR also has some drawbacks, including:

Increased complexity: SSR can add complexity to the development and deployment of a web application.
Increased cost: SSR can increase the cost of hosting a web application.

**Dangerous URL scheme**
A dangerous URL scheme is a URL that can be used to exploit a vulnerability in a web application. For example, a URL that starts with javascript: can be used to execute arbitrary JavaScript code.

To mitigate the risk of dangerous URL schemes, developers should use a web application firewall (WAF) to block these types of URLs. Developers should also carefully validate all user input before using it to generate URLs.

**Escape hatches**
Escape hatches are code that can be used to bypass security controls. For example, an escape hatch might allow a user to bypass a CAPTCHA or to access a restricted area of a web application.

To mitigate the risk of escape hatches, developers should carefully review all code for potential security vulnerabilities. Developers should also implement security controls that make it difficult for users to bypass these controls.

**Dangerous setInnerHTML**
The setInnerHTML method can be used to set the HTML content of an element. However, this method can be used to inject malicious code into a web page.

To mitigate the risk of setInnerHTML being used to inject malicious code, developers should carefully validate all user input before using it to set the HTML content of an element. Developers should also use a WAF to block known malicious HTML patterns.

**Cross-site Scripting (XSS)**
XSS is a type of vulnerability that allows an attacker to inject malicious code into a web application. This code can then be executed by the victim's browser, allowing the attacker to steal cookies, hijack sessions, or even take complete control of the victim's browser.

XSS vulnerabilities can occur in any part of a web application, but they are particularly common in React and Angular applications because these frameworks use a lot of client-side JavaScript. This JavaScript code is often user-generated, which makes it more vulnerable to XSS attacks.

In 2017, a major XSS vulnerability was discovered in the React Router library. This vulnerability allowed attackers to inject malicious code into any React application that used the Router library. The vulnerability was exploited by attackers to steal cookies and hijack sessions.

**Improper Access Control**
Improper access control is another common vulnerability that can occur in React and Angular applications. This vulnerability occurs when an attacker is able to access data or functionality that they should not be able to access.

Improper access control can occur for a variety of reasons, such as:

 - Using weak passwords or security practices
 - Failing to properly sanitize user input
 - Not using role-based access control

**Open Redirects**
Open redirects are a type of vulnerability that allows an attacker to redirect a victim's browser to an arbitrary URL. This can be used to trick the victim into visiting a malicious website, or to redirect them away from a legitimate website.

Open redirects can occur in React and Angular applications if they use unsanitized user input to generate URLs. For example, if an application allows users to enter a URL in a comment field, an attacker could enter a malicious URL that redirects the victim to a malicious website.

In 2019, a major open redirect vulnerability was discovered in the React Router library. This vulnerability allowed attackers to redirect users to any URL they wanted by exploiting a flaw in the library's URL validation mechanism.

**Cross-site Request Forgery (CSRF)**
CSRF is a type of vulnerability that allows an attacker to force a victim to perform an action on a web application without their knowledge or consent. This can be used to steal data, hijack sessions, or even take complete control of the victim's account.

CSRF vulnerabilities can occur in any web application, but they are particularly common in React and Angular applications because these frameworks use a lot of AJAX requests. AJAX requests are made by the client-side JavaScript code, which makes them more vulnerable to CSRF attacks.

In 2020, a major CSRF vulnerability was discovered in the Angular Material library. This vulnerability allowed attackers to force users to perform actions on any website they visited by exploiting a flaw in the library's AJAX request handling mechanism.

**SQL Injection**
SQL injection is a type of vulnerability that allows an attacker to inject malicious SQL code into a web application. This code can then be executed by the database server, allowing the attacker to steal data, modify data, or even take complete control of the database server.

SQL injection vulnerabilities can occur in any part of a web application that interacts with a database, but they are particularly common in React and Angular applications because these frameworks use a lot of dynamic SQL. Dynamic SQL is SQL that is generated at runtime, which makes it more vulnerable to SQL injection attacks.

In 2016, a major SQL injection vulnerability was discovered in the React Router library. This vulnerability allowed attackers to inject malicious SQL code into any React application that used the Router library. The vulnerability was exploited by attackers to steal data from the database.

**Insecure Deserialization**
Insecure deserialization is a type of vulnerability that allows an attacker to exploit a flaw in the deserialization process to execute arbitrary code. Deserialization is the process of converting a serialized object back into its original form. Serialization is the process of converting an object into a format that can be stored or transmitted.

Insecure deserialization vulnerabilities can occur in any application that deserializes untrusted data. This includes React and Angular applications that use JSON or XML to store data.

In 2018, a major insecure deserialization vulnerability was discovered in the Angular Material library. This vulnerability allowed attackers to exploit a flaw in the library's deserialization mechanism to execute arbitrary code. The vulnerability was exploited by attackers to take control of victim's computers.

**Information Disclosure**
Information disclosure is a type of vulnerability that allows an attacker to access sensitive data that should not be publicly accessible. This can include data such as user passwords, credit card numbers, or private messages.

Information disclosure vulnerabilities can occur in any part of a web application, but they are particularly common in React and Angular applications because these frameworks use a lot of client-side JavaScript. This JavaScript code is often user-generated, which makes it more vulnerable to information disclosure attacks.

In 2019, a major information disclosure vulnerability was discovered in the React Router library. This vulnerability allowed attackers to view the source code of any React application that used the Router library. The vulnerability was exploited by attackers to steal sensitive information, such as user passwords and credit card numbers.

These are just a few of the most common vulnerabilities that can occur in React and Angular applications. It is important to be aware of these vulnerabilities and to take steps to mitigate them. This can be done by using secure coding practices, implementing security controls, and keeping software up to date

**Conclusion**
React and Angular are powerful frameworks that can be used to build secure web applications. However, it is important to be aware of the security vulnerabilities that can occur in these frameworks. By taking steps to mitigate these vulnerabilities, developers can help to protect their applications from attack.