CVE-2022-20756 Explained : Impact and Mitigation

A vulnerability in the RADIUS feature of Cisco Identity Services Engine (ISE) could allow an unauthenticated, remote attacker to cause the affected system to stop processing RADIUS packets. This could lead to authentication/authorization timeouts and denial of legitimate requests.

Understanding CVE-2022-20756

This CVE describes a denial-of-service vulnerability in the RADIUS service of Cisco ISE, impacting system availability and network access.

What is CVE-2022-20756?

CVE-2022-20756 is a vulnerability in Cisco ISE that could be exploited by remote attackers to disrupt RADIUS packet processing, resulting in service denial and access interruptions.

The Impact of CVE-2022-20756

The vulnerability poses a high availability impact, with the potential for legitimate requests to be denied access due to authentication/authorization timeouts.

Technical Details of CVE-2022-20756

This section outlines the vulnerability description, affected systems and versions, and the exploitation mechanism.

Vulnerability Description

Improper handling of certain RADIUS requests in Cisco ISE leads to the vulnerability, allowing attackers to disrupt RADIUS packet processing.

Affected Systems and Versions

The vulnerability affects Cisco Identity Services Engine Software, with specific versions marked as affected.

Exploitation Mechanism

Attackers can exploit this vulnerability by attempting to authenticate to a network using Cisco ISE as the RADIUS server, causing service disruptions.

Mitigation and Prevention

Discover steps to mitigate the immediate threat, implement long-term security practices, and stay updated with patching.

Immediate Steps to Take

To recover from the RADIUS packet processing disruption, a manual restart of the affected Policy Service Node (PSN) is necessary.

Long-Term Security Practices

Enhance network security by enforcing strict access controls and continuously monitoring for unusual network activities.

Patching and Updates

Stay informed about security updates and patches released by Cisco to address this vulnerability.