CVE-2024-21606 Explained : Impact and Mitigation

This CVE-2024-21606 article provides an overview of a security vulnerability identified in Juniper Networks Junos OS on SRX Series, impacting specific versions.

Understanding CVE-2024-21606

This vulnerability, known as CVE-2024-21606, involves a Double Free vulnerability in the flow processing daemon (flowd) of Juniper Networks Junos OS on SRX Series, allowing a network-based, unauthenticated attacker to cause a Denial of Service (DoS) under certain conditions.

What is CVE-2024-21606?

The Double Free vulnerability in the flowd of Juniper Networks Junos OS on SRX Series can be exploited by a remote attacker to trigger a flowd crash and subsequent restart. This issue specifically affects Juniper Networks Junos OS versions prior to 20.4R3-S8, 21.2R3-S6, 21.3R3-S5, 21.4R3-S5, 22.1R3-S3, 22.2R3-S3, 22.3R3-S1, and versions earlier than 22.4R2-S2, 22.4R3.

The Impact of CVE-2024-21606

The vulnerability's impact lies in the potential for a network-based, unauthenticated attacker to exploit the Double Free flaw, leading to a Denial of Service (DoS). In the context of a remote access VPN scenario and with a specific configuration present, a flowd crash and subsequent restart can disrupt services.

Technical Details of CVE-2024-21606

This section delves deeper into the vulnerability's technical aspects.

Vulnerability Description

The Double Free vulnerability in the flow processing daemon (flowd) of Juniper Networks Junos OS on SRX Series enables a network-based, unauthenticated attacker to instigate a Denial of Service (DoS) by triggering a flowd crash and restart.

Affected Systems and Versions

Juniper Networks Junos OS on SRX Series versions earlier than 20.4R3-S8, 21.2R3-S6, 21.3R3-S5, 21.4R3-S5, 22.1R3-S3, 22.2R3-S3, 22.3R3-S1, and versions before 22.4R2-S2, 22.4R3 are susceptible to this vulnerability.

Exploitation Mechanism

In a remote access VPN scenario involving a specific configuration, a malicious network-based attacker can exploit the "tcp-encap-profile" to send specific packets that trigger a flowd crash and subsequent restart.

Mitigation and Prevention

Understanding how to mitigate and prevent the CVE-2024-21606 vulnerability is crucial for maintaining network security.

Immediate Steps to Take

Update to the patched versions provided by Juniper Networks (Junos OS 20.4R3-S8, 21.2R3-S6, 21.3R3-S5, 21.4R3-S5, 22.1R3-S3, 22.2R3-S3, 22.3R3-S1, 22.4R2-S2, 22.4R3, 23.2R1, and subsequent releases) to address and resolve the vulnerability.

Long-Term Security Practices

Regularly monitor for security updates from Juniper Networks and apply patches promptly to safeguard your network infrastructure against known vulnerabilities.

Patching and Updates

Ensure all affected systems running Juniper Networks Junos OS on SRX Series are updated to the latest patched versions to mitigate the risks posed by CVE-2024-21606.

This comprehensive guide provides insight into CVE-2024-21606, its impact, technical details, and measures to mitigate the associated risk effectively. It is essential for organizations to prioritize security updates and take proactive steps to protect their systems from potential threats.