CVE-2024-21595 : What You Need to Know

This is a detailed overview of CVE-2024-21595, a vulnerability identified in Juniper Networks Junos OS.

Understanding CVE-2024-21595

CVE-2024-21595 is an Improper Validation of Syntactic Correctness of Input vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS. It allows a network-based, unauthenticated attacker to cause a Denial of Service (DoS) by sending a high rate of specific ICMP traffic to a device with VXLAN configured. This results in a deadlock of the PFE, making the device unresponsive and requiring a manual restart to recover.

What is CVE-2024-21595?

The vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS allows an attacker to trigger a DoS by exploiting VXLAN configurations on affected devices, including EX4100, EX4400, EX4600, and QFX5000 Series.

The Impact of CVE-2024-21595

The impact of CVE-2024-21595 is classified as HIGH. The availability of the affected systems is significantly impacted, leading to device unresponsiveness and requiring manual intervention to recover.

Technical Details of CVE-2024-21595

This section covers the technical aspects of CVE-2024-21595.

Vulnerability Description

The vulnerability arises from the improper validation of input syntax in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS, allowing an unauthenticated attacker to trigger a DoS by sending specific ICMP traffic to devices with VXLAN configurations.

Affected Systems and Versions

The issue affects Juniper Networks Junos OS versions prior to 21.4R3-S4, 22.1R3-S3, 22.2R3-S1, 22.3R2-S2/22.3R3, 22.4R2, and 23.1R2, on EX4100, EX4400, EX4600, and QFX5000 Series devices.

Exploitation Mechanism

To exploit CVE-2024-21595, an attacker needs to send a high rate of specific ICMP traffic to a device with VXLAN configured, causing a deadlock in the Packet Forwarding Engine.

Mitigation and Prevention

Here are the steps to mitigate and prevent the exploitation of CVE-2024-21595.

Immediate Steps to Take

Update affected devices by applying the software releases that resolve the specific issue: Junos OS 21.4R3-S4, 22.1R3-S3, 22.2R3-S1, 22.3R2-S2, 22.3R3, 22.4R2, 23.1R2, 23.2R1, and all subsequent releases provided by Juniper Networks.

Long-Term Security Practices

Implementing robust network security measures, staying informed about vulnerabilities, and promptly applying patches can enhance long-term security against potential exploits.

Patching and Updates

Regularly monitor security advisories from Juniper Networks to identify and address vulnerabilities promptly. Keep systems up to date with the latest patches and updates to mitigate potential risks.

Remember, proactive security measures and timely updates play a crucial role in safeguarding network infrastructure from potential threats.