CVE-2021-22889 : Exploit Details and Defense Strategies

Revive Adserver before v5.2.0 is vulnerable to a reflected XSS vulnerability allowing attackers to execute injected JavaScript code.

Understanding CVE-2021-22889

This vulnerability in Revive Adserver before v5.2.0 allows for a reflected XSS attack, potentially enabling malicious actors to execute arbitrary code.

What is CVE-2021-22889?

CVE-2021-22889 is a reflected Cross-Site Scripting (XSS) vulnerability in the

statsBreakdown

parameter of stats.php in Revive Adserver before v5.2.0. This flaw arises from the lack of escaping single quotes, which can be exploited by tricking a user into clicking a specially crafted URL.

The Impact of CVE-2021-22889

A threat actor could exploit this vulnerability to execute arbitrary JavaScript code in the context of the user's session, leading to potential unauthorized actions and data theft.

Technical Details of CVE-2021-22889

This section covers specific technical details related to the CVE.

Vulnerability Description

The vulnerability is due to the failure to escape single quotes in the

statsBreakdown

parameter, allowing an attacker to insert and execute malicious code.

Affected Systems and Versions

Revive Adserver versions before v5.2.0 are impacted by this vulnerability.

Exploitation Mechanism

An attacker can craft a URL containing malicious code and trick a user with access to click on the URL, initiating the execution of the injected script.

Mitigation and Prevention

Protecting against CVE-2021-22889 requires immediate actions and long-term security practices.

Immediate Steps to Take

Upgrade Revive Adserver to version 5.2.0 or newer to eliminate the vulnerability.
Educate users to avoid clicking on untrusted links or URLs.

Long-Term Security Practices

Regularly update and patch software to address known vulnerabilities.
Implement web application security best practices such as input validation and output encoding.

Patching and Updates

Stay informed about security advisories and updates from Revive Adserver to apply patches promptly to secure your systems.