CVE-2021-35478 : Security Advisory and Response

Nagios Log Server before version 2.1.9 is impacted by a Reflected Cross-Site Scripting (XSS) vulnerability in the dropdown box for the alert history and audit log function. This vulnerability affects all parameters used for filtering and can be exploited by users who open a malicious link or visit a compromised website.

Understanding CVE-2021-35478

This section will provide insights into the nature and severity of the CVE-2021-35478 vulnerability.

What is CVE-2021-35478?

The vulnerability in Nagios Log Server before 2.1.9 allows for Reflected XSS in the alert history and audit log dropdown box. Attackers can exploit this by manipulating parameters in crafted links or malicious web pages.

The Impact of CVE-2021-35478

Users who interact with the affected dropdown box are at risk of having their data exposed or being redirected to malicious websites, potentially leading to further compromise.

Technical Details of CVE-2021-35478

This section will delve into the specifics and technical aspects of CVE-2021-35478.

Vulnerability Description

The Reflected XSS vulnerability in Nagios Log Server stems from improper input validation in the alert history and audit log dropdown, enabling attackers to execute scripts in the context of a user's session.

Affected Systems and Versions

Nagios Log Server versions prior to 2.1.9 are confirmed to be impacted by this vulnerability, exposing users of these versions to exploitation.

Exploitation Mechanism

By enticing users to click on specially crafted links or visit malicious web pages, attackers can trigger the XSS payload, leading to unauthorized execution of scripts in the victim's browser.

Mitigation and Prevention

In this section, we will explore the steps to mitigate the risks associated with CVE-2021-35478.

Immediate Steps to Take

Users of Nagios Log Server should update to version 2.1.9 or later to mitigate the risk of exploitation. Additionally, exercise caution when clicking on links from untrusted sources.

Long-Term Security Practices

Regular security training, ensuring software is up-to-date, and implementing strict input validation practices can help prevent XSS vulnerabilities like CVE-2021-35478.

Patching and Updates

Staying informed about security updates from Nagios and promptly applying patches is crucial to protecting systems from known vulnerabilities.