jQuery, one of the most popular JavaScript libraries, has been instrumental in simplifying client-side scripting of HTML. However, its widespread use has also made it a target for various security vulnerabilities over the years.

In this article, we will look at five notable jQuery vulnerabilities, explore their implications, and discuss the measures to mitigate them.

1) Cross-site Scripting (XSS) Pre-1.9.0

This vulnerability allows attackers to perform XSS attacks by exploiting the way jQuery differentiated selectors from HTML in versions before 1.9.0. Such attacks enable malicious scripts to be executed in the user's browser context, potentially leading to unauthorized access or information theft.

• CVE: CVE-2012-6708

• Published: The vulnerability was published on April 26, 2019.

• How to fix it: To mitigate this vulnerability, developers should update to jQuery version 1.9.0 or later, which contains the necessary fixes to prevent this type of XSS attack.

2) Prototype Pollution

Prototype Pollution affects jQuery versions before 3.4.0, where attackers can modify the prototype of a base object, leading to potential application manipulation or execution of unintended code.

• CVE: CVE-2019-11358

• Published: The vulnerability was published on April 20, 2019.

• How to fix it: The fix involves updating jQuery to version 3.4.0 or higher. This update includes a patch that prevents attackers from modifying the prototype properties of objects.

3) Cross-site Scripting (XSS) in 1.2 to before 3.5.0

This XSS vulnerability exists in versions of jQuery ranging from 1.2 to before 3.5.0, where HTML handling from untrusted sources can lead to code execution.

• CVE: CVE-2020-11022

• Published: The vulnerability was published on April 28, 2020.

• How to fix it: To resolve this issue, developers should upgrade to jQuery version 3.5.0 or later. This version includes important security enhancements that sanitize HTML code effectively, preventing XSS attacks.

4) Cross-site Scripting (XSS) in 1.0.3 to before 3.5.0

Similar to the previous XSS vulnerability, this issue also allows the execution of untrusted code via HTML containing <option> elements in jQuery versions from 1.0.3 to before 3.5.0.

• CVE: CVE-2020-11023

• Published: The vulnerability was published on April 28, 2020.

• How to fix it: Updating jQuery to version 3.5.0 or newer is necessary to mitigate this vulnerability. The newer versions have corrected the flaw by ensuring that HTML is sanitized properly before being processed.

5) Denial of Service (DoS) 3.0.0-rc1

jQuery version 3.0.0-rc1 introduced a vulnerability that could lead to a Denial of Service (DoS) attack due to an issue with attribute name handling, causing infinite recursion.

• CVE: CVE-2016-10707

• Published: The vulnerability was published on January 23, 2018.

• How to fix it: The remedy for this DoS vulnerability is to upgrade to the stable release of jQuery 3.0.0 or later versions, which have addressed and resolved this specific issue, ensuring stability and preventing service disruptions.