CVE-2023-36838 : Security Advisory and Response

A detailed overview of CVE-2023-36838 focusing on the Out-of-bounds Read vulnerability in Juniper Networks Junos OS on SRX Series that can lead to a Denial of Service (DoS) attack.

Understanding CVE-2023-36838

This section provides insights into the vulnerability, its impact, technical details, and mitigation strategies.

What is CVE-2023-36838?

CVE-2023-36838 is an Out-of-bounds Read vulnerability in the flow processing daemon (flowd) of Juniper Networks Junos OS on SRX Series. It allows a local, authenticated attacker with low privileges to trigger a Denial of Service (DoS) incident by executing a specific CLI command.

The Impact of CVE-2023-36838

The vulnerability can result in a temporary traffic interruption on the SRX Series device and could potentially lead to a sustained DoS attack if the malicious command is repeatedly executed. This can disrupt network operations and impact service availability.

Technical Details of CVE-2023-36838

This section delves into the specifics of the vulnerability, including its description, affected systems, and the exploitation mechanism.

Vulnerability Description

The Out-of-bounds Read vulnerability in flowd allows a low-privileged user to crash the service, resulting in a temporary traffic disruption until the process restarts. Continual execution of the command can lead to a sustained DoS attack.

Affected Systems and Versions

Juniper Networks Junos OS on SRX Series versions prior to 20.2R3-S7, 20.3R1 and later versions, 20.4R3-S6, 21.1R3-S5, 21.2R3-S4, 21.3R3-S4, 21.4R3-S3, 22.1R3-S1, 22.2R3, 22.3R2, and 22.4R1-S1, 22.4R2 are affected by this vulnerability.

Exploitation Mechanism

As of now, Juniper SIRT has not detected any active exploitation of this vulnerability.

Mitigation and Prevention

In this section, we outline the immediate steps to take and long-term security practices to mitigate the risks posed by CVE-2023-36838.

Immediate Steps to Take

Juniper advises users to update their systems to the patched versions: Junos OS 20.2R3-S7, 20.4R3-S6, 21.1R3-S5, 21.2R3-S4, 21.3R3-S4, 21.4R3-S3, 22.1R3-S1, 22.2R3, 22.3R2, 22.4R1-S1, 22.4R2, 23.1R1, or any subsequent releases to address this vulnerability.

Long-Term Security Practices

It is recommended to follow best practices such as regular software updates, network segmentation, and access control measures to enhance overall security posture.

Patching and Updates

Juniper has released software updates for Junos OS versions mentioned above to fix the vulnerability. Users are urged to apply these patches promptly to prevent potential exploits.