CVE-2021-33339 : Exploit Details and Defense Strategies

A detailed article about the Cross-site scripting (XSS) vulnerability in Liferay Portal and Liferay DXP.

Understanding CVE-2021-33339

This CVE identifies a cross-site scripting (XSS) vulnerability in the Fragment module of Liferay Portal versions 7.2.1 through 7.3.4, and Liferay DXP 7.2 before fix pack 9.

What is CVE-2021-33339?

The CVE-2021-33339 refers to a security flaw that allows remote attackers to inject arbitrary web script or HTML through the _com_liferay_site_admin_web_portlet_SiteAdminPortlet_name parameter in affected Liferay Portal and DXP versions.

The Impact of CVE-2021-33339

This vulnerability could be exploited by malicious actors to execute script code in the context of an unsuspecting user's browser, potentially leading to unauthorized actions or data theft.

Technical Details of CVE-2021-33339

Below are the technical aspects related to CVE-2021-33339:

Vulnerability Description

The XSS flaw in the Fragment module of Liferay Portal and DXP versions specified allows attackers to insert malicious scripts into web pages viewed by other users.

Affected Systems and Versions

Liferay Portal versions 7.2.1 through 7.3.4, and Liferay DXP 7.2 before fix pack 9 are impacted by this vulnerability.

Exploitation Mechanism

Malicious actors can exploit this vulnerability by injecting crafted scripts or HTML code via the vulnerable _com_liferay_site_admin_web_portlet_SiteAdminPortlet_name parameter.

Mitigation and Prevention

To address CVE-2021-33339, consider the following mitigation strategies:

Immediate Steps to Take

Upgrade the affected Liferay Portal and Liferay DXP versions to the latest releases that contain security patches.
Apply web security best practices to mitigate the risk of XSS attacks.

Long-Term Security Practices

Regularly monitor security advisories from Liferay to stay informed about emerging threats and fixes.
Educate administrators and developers on secure coding practices to prevent XSS vulnerabilities.

Patching and Updates

Ensure timely patching of your Liferay installations by applying security updates released by the vendor.