CVE-2021-35976 Explained : Impact and Mitigation

A detailed overview of CVE-2021-35976, a vulnerability in Plesk Obsidian that allows for reflected XSS attacks through the /plesk-site-preview/ PATH, enabling an attacker to run malicious JavaScript code in a victim's browser.

Understanding CVE-2021-35976

This section will cover the specifics of the CVE-2021-35976 vulnerability.

What is CVE-2021-35976?

The vulnerability in Plesk Obsidian version 18.0.0 through 18.0.32 on Linux permits reflected XSS via the /plesk-site-preview/ PATH, labeled as PFSI-62467. An attacker could trigger JavaScript code execution in the victim's browser by leveraging the link to preview sites hosted on the server, without requiring authentication.

The Impact of CVE-2021-35976

The impact of this vulnerability includes the ability for malicious actors to inject and execute arbitrary JavaScript code in the context of a user's session, potentially leading to various attacks like data theft, account compromise, and unauthorized access.

Technical Details of CVE-2021-35976

In this section, we will delve into the technical aspects of CVE-2021-35976.

Vulnerability Description

The flaw in Plesk Obsidian allows for the insertion of malicious scripts via the preview feature, leading to XSS attacks that could compromise user data and system integrity.

Affected Systems and Versions

Plesk Obsidian versions 18.0.0 through 18.0.32 on the Linux platform are susceptible to this vulnerability, exposing systems running these versions to potential exploitation.

Exploitation Mechanism

Exploiting CVE-2021-35976 involves crafting a URL that contains malicious JavaScript code and sending it to a target victim. Upon clicking the link, the script executes in the victim's browser, enabling the attacker to carry out further malicious actions.

Mitigation and Prevention

This section will outline the necessary steps to mitigate the risks posed by CVE-2021-35976.

Immediate Steps to Take

Users are advised to apply security patches provided by Plesk to address the vulnerability. Additionally, administrators should restrict access to the preview feature and monitor for any suspicious activities.

Long-Term Security Practices

In the long term, organizations should prioritize regular security assessments, implement web application firewalls, and educate users about the risks of clicking on untrusted links to prevent similar attacks.

Patching and Updates

Staying up to date with security patches released by Plesk is crucial in safeguarding systems against known vulnerabilities like CVE-2021-35976.