CVE-2021-0233 : Security Advisory and Response

A vulnerability in Juniper Networks Junos OS ACX500 Series, ACX4000 Series, may allow an attacker to cause a Denial of Service (DoS) by sending a high rate of specific packets to the device, resulting in a Forwarding Engine Board (FFEB) crash.

Understanding CVE-2021-0233

This CVE involves a Denial of Service (DoS) vulnerability in Juniper Networks Junos OS ACX500 Series, ACX4000 Series, impacting versions prior to 17.4R3-S2.

What is CVE-2021-0233?

The vulnerability in Junos OS ACX500 Series, ACX4000 Series allows attackers to trigger a DoS condition by sending specific packets at a high rate, leading to an FFEB crash.

The Impact of CVE-2021-0233

The CVSS score for this vulnerability is 7.5 (High), with a low attack complexity and network-based attack vector. It can result in a sustained DoS condition on affected devices.

Technical Details of CVE-2021-0233

This section covers the technical aspects of the vulnerability.

Vulnerability Description

Incomplete filtering of specific packets can lead to a FFEB crash, causing a DoS condition on the affected devices.

Affected Systems and Versions

Junos OS ACX500 Series, ACX4000 Series versions before 17.4R3-S2 are vulnerable to this DoS exploit.

Exploitation Mechanism

There are no known instances of malicious exploitation of this vulnerability by Juniper SIRT.

Mitigation and Prevention

To address CVE-2021-0233, follow these mitigation steps:

Immediate Steps to Take

Upgrade to Junos OS 17.4R3-S2 or later to eliminate this vulnerability.

Long-Term Security Practices

Regularly monitor for updates and patches released by Juniper Networks to ensure system security.

Patching and Updates

Juniper Networks has released updated software versions starting from 17.4R3-S2 to resolve this specific vulnerability.