CVE-2023-36831 Explained : Impact and Mitigation

An Improper Check or Handling of Exceptional Conditions vulnerability in the UTM (Unified Threat Management) Web-Filtering feature of Juniper Networks Junos OS on SRX Series causes a jbuf memory leak leading to a Denial of Service (DoS) condition when accessing certain websites. This article provides insights into CVE-2023-36831 affecting Junos OS.

Understanding CVE-2023-36831

This section delves into the details of the CVE-2023-36831 vulnerability, its impact, technical description, affected systems, exploitation mechanism, mitigation, and prevention methods.

What is CVE-2023-36831?

An Improper Check or Handling of Exceptional Conditions vulnerability in the UTM Web-Filtering feature of Juniper Networks Junos OS on SRX Series leads to a jbuf memory leak, causing a Denial of Service condition. Only SSL Proxy and UTM Web-Filtering configurations are affected.

The Impact of CVE-2023-36831

The vulnerability results in a jbuf memory leak that can be exploited through specific website access, leading to a DoS condition. System reboot is required for service restoration. Product versions prior to specified releases are vulnerable.

Technical Details of CVE-2023-36831

This section provides in-depth technical information about the vulnerability, affected systems, and the exploitation mechanism.

Vulnerability Description

The CVE-2023-36831 vulnerability in Junos OS on SRX Series causes a jbuf memory leak under SSL Proxy and UTM Web-Filtering configurations, resulting in a DoS condition that requires system reboot for service restoration.

Affected Systems and Versions

Affected systems include Juniper Networks Junos OS on SRX Series with specific versions: 22.2 prior to 22.2R3, 22.3 prior to 22.3R2-S1 and 22.3R3, 22.4 prior to 22.4R1-S2 and 22.4R2. Versions before 22.2R2 are not impacted.

Exploitation Mechanism

Exploitation of this vulnerability may lead to a DoS condition but Juniper SIRT has not detected any malicious exploitation at the time of publishing.

Mitigation and Prevention

This section outlines steps to mitigate the CVE-2023-36831 vulnerability and prevent potential exploitation.

Immediate Steps to Take

Ensure immediate implementation of the provided software updates to resolve the vulnerability: Junos OS 22.2R3, 22.3R2-S1, 22.3R3, 22.4R1-S2, 22.4R2, 23.1R1, and subsequent releases.

Long-Term Security Practices

Regularly update Junos OS to the latest versions as they include patches and enhancements to address security loopholes and prevent vulnerabilities like CVE-2023-36831.

Patching and Updates

Stay informed about security advisories from Juniper Networks and promptly apply patches and updates to safeguard systems against known vulnerabilities.