CVE-2021-0225 : What You Need to Know

Juniper Networks Junos OS Evolved is affected by an improper check for unusual conditions, leading to stateless firewall filter misconfigurations. Learn about the impact, technical details, and mitigation strategies for CVE-2021-0225.

Understanding CVE-2021-0225

This vulnerability in Junos OS Evolved may cause issues with the 'policer' action in firewall configurations, affecting versions 19.1R1-EVO to 20.3R1-S2-EVO, 20.3R2-EVO.

What is CVE-2021-0225?

Juniper Networks Junos OS Evolved is prone to misconfigurations in stateless firewall filters due to improper checks for unusual conditions, impacting specific versions.

The Impact of CVE-2021-0225

The vulnerability could allow threat actors to bypass firewall policies, potentially leading to unauthorized network access and data breaches.

Technical Details of CVE-2021-0225

The vulnerability has a CVSS v3.1 base score of 5.8, indicating a medium severity issue with low attack complexity and network attack vectors.

Vulnerability Description

An improper check for unusual conditions in Junos OS Evolved affects the functionality of stateless firewall filters using the 'policer' action.

Affected Systems and Versions

Junos OS Evolved versions 19.1R1-EVO to 20.3R1-S2-EVO, 20.3R2-EVO are vulnerable to this issue.

Exploitation Mechanism

Juniper SIRT has not detected any active malicious exploits targeting this vulnerability.

Mitigation and Prevention

To address CVE-2021-0225, users should update Junos OS Evolved to versions 20.3R1-S2-EVO, 20.3R2-EVO, 20.4R1-EVO, or later releases.

Immediate Steps to Take

Users are advised to apply the provided software updates to resolve the firewall filter misconfiguration issue.

Long-Term Security Practices

Implement robust firewall policies and regularly monitor network traffic to detect any unauthorized access attempts.

Patching and Updates

Juniper Networks has released updated software versions to address the stateless IP firewall filter vulnerability.