Picture this: A user on your network casually explores the internet and scrolls through a website’s comment section.

However, a lurking threat known as cross-site scripting (XSS) is poised to exploit vulnerabilities and steal their session cookies, which includes sensitive data such as their logon credentials.

But how does this nefarious scheme unfold, and what other open-source vulnerabilities could be exploited in the process?

Cross-site scripting

The following code snippet illustrates XSS:

//Vulnerable JavaScript code in a comment section

const userComment = ‘<img src=a onerror=”stealCookies()”>Check out this cool image!</img>’;

function stealCookies() {

  const stolenCookies = document.cookie;

  // Send stolen cookies to a remote server


In the code above, the image tag contains a onerror attribute, triggering the execution of the stealCookies function. This function snatches the user’s cookies and paves the way for unauthorized access to sensitive information.

Cross-Site Request Forgery (CSRF)

CSRF attacks occur when an attacker tricks a user’s browser into making an unintentional request to a different site where the user is authenticated. This could lead to actions being performed on the user’s behalf without their consent.


<form action=”https://website.com/update-email” method=”POST”>

  <input type=”hidden” name=”email” value=”iamahacker@example.com”>

  <input type=”submit” value=”Update Email”>



In this example, a user who is authenticated on a website may unknowingly submit a form that changes their email address to one specified by the attacker. The attacker can now reset the password to that account by clicking on the Forgot password? link. The verification code will be sent to the updated attacker’s email, and the attacker can change the password and take complete control of the account.

How can you detect open-source vulnerabilities that lurk online?

To detect open-source vulnerabilities:

  • Keep your open-source libraries and frameworks up to date. Regularly check for security patches and updates to eliminate known vulnerabilities.

  • Implement and enforce a comprehensive content security policy (CSP) to control the sources of scripts and prevent unauthorized code execution.

  • Set the cookie attribute SameSite = “Strict”. The SameSite attribute is responsible for preventing cookie data transfer during cross-domain requests.

  • Monitor user sessions and web activities closely using a security solution, such as a SIEM, which can track and audit user sessions and online activities in real time. Log360, a SIEM solution from ManageEngine, can be an indispensable addition to your security realm.

If your users try to communicate with a malicious website, the threat intelligence module in Log360 will provide in-depth analytics such as why the URL, IP address, or domain name is malicious, why it is tagged as malicious, when it last appeared on the threat list, and the geolocation of the malicious entities.


You can execute automated workflows to tweak firewall policies instantly to prevent your users from sending and receiving data from such malicious entities.

You can also mark a list of applications as Sanctioned using the CASB module of Log360 to let your network users access the applications freely. You can mark malicious and unwanted applications as Unsanctioned to restrict access to such applications.

You can try these features in your environment for free by downloading the fully functional30-day trial of Log360.

Shehnaaz N
Product Marketing Specialist