In this tutorial, we will discuss CVE-2024-21490, a high-severity vulnerability affecting AngularJS related to Regex Denial of Service (ReDoS). We will explain what the vulnerability is, how it can be exploited, and how you can mitigate the risk of this vulnerability in your AngularJS applications.
What is CVE-2024-21490?
CVE-2024-21490 is a security vulnerability that was discovered in AngularJS, a popular JavaScript framework for building dynamic web applications. The vulnerability is related to Regular Expression Denial of Service (ReDoS), which occurs when a malicious user can craft a regex pattern that takes a long time to execute, causing the application to become unresponsive or crash.
Exploiting this vulnerability can lead to a denial of service attack, where an attacker can disrupt the normal operation of the AngularJS application by sending malicious inputs that trigger the ReDoS vulnerability.
How to exploit CVE-2024-21490?
To exploit CVE-2024-21490, an attacker can create a malicious input that triggers the ReDoS vulnerability in the vulnerable AngularJS application. This can be done by crafting a regex pattern that contains a large number of nested quantifiers, such as repetitions or alternations, which can lead to exponential backtracking and cause the regex engine to consume a significant amount of CPU resources.
For example, a malicious regex pattern like (a+)+ can cause a ReDoS vulnerability in an AngularJS application by matching against a string with a large number of ‘a’ characters, leading to a denial of service condition.
Mitigating the risk of CVE-2024-21490 in AngularJS:
To mitigate the risk of CVE-2024-21490 in your AngularJS applications, follow these best practices:
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Update AngularJS: Check if there are any patches or updates available for AngularJS that address the ReDoS vulnerability. It is important to keep your AngularJS framework up to date to protect against known security issues.
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Limit regex complexity: Avoid using complex regex patterns in your AngularJS application that can lead to ReDoS vulnerabilities. Use simpler regex patterns whenever possible and restrict the use of nested quantifiers to prevent regex backtracking.
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Input validation: Implement input validation mechanisms in your AngularJS application to sanitize user inputs and prevent malicious inputs that can trigger the ReDoS vulnerability. Use whitelisting or blacklisting techniques to filter out potentially harmful regex patterns.
- Rate limiting: Implement rate limiting mechanisms in your AngularJS application to restrict the number of regex matching operations that can be performed within a certain time frame. This can help prevent an attacker from overwhelming the application with malicious inputs.
By following these best practices, you can reduce the risk of CVE-2024-21490 in your AngularJS applications and enhance the security of your web applications. Remember to stay informed about the latest security vulnerabilities and updates for AngularJS to protect your application from potential threats.
