CVE-2023-28981 Explained : Impact and Mitigation

This CVE record was published by Juniper on April 17, 2023. It addresses an Improper Input Validation vulnerability in Juniper Networks Junos OS and Junos OS Evolved that can lead to a Denial of Service (DoS) attack.

Understanding CVE-2023-28981

This vulnerability in Junos OS and Junos OS Evolved can be exploited by an unauthenticated, adjacent attacker to cause a denial of service. It occurs when a specifically malformed IPv6 router advertisement packet is received, leading to memory corruption and an rpd crash.

What is CVE-2023-28981?

CVE-2023-28981 is an Improper Input Validation vulnerability in Juniper Networks Junos OS and Junos OS Evolved that allows an attacker to trigger a DoS attack by sending a malformed IPv6 router advertisement packet to the target system.

The Impact of CVE-2023-28981

The impact of this vulnerability is the potential crash of the rpd process, resulting in a denial of service condition on the affected Junos OS and Junos OS Evolved systems.

Technical Details of CVE-2023-28981

This section provides more insight into the vulnerability, the affected systems and versions, as well as the exploitation mechanism.

Vulnerability Description

The vulnerability arises due to improper input validation in the kernel of Juniper Networks Junos OS and Junos OS Evolved when processing IPv6 router advertisements, leading to memory corruption and a crash of the rpd process.

Affected Systems and Versions

Juniper Networks Junos OS versions 20.3 to 22.1 and Junos OS Evolved versions 20.3R1-EVO to 22.1-EVO are affected by this vulnerability, with specific versions being vulnerable until the latest patched releases.

Exploitation Mechanism

An unauthenticated, adjacent attacker can exploit this vulnerability by sending a specifically crafted malformed IPv6 router advertisement packet to the target system, causing memory corruption and triggering the rpd crash.

Mitigation and Prevention

To address CVE-2023-28981, immediate steps need to be taken to mitigate the risk and prevent potential exploitation.

Immediate Steps to Take

If router advertisements are not essential, incoming RAs can be filtered and dropped using firewall filters to prevent the exploitation of this vulnerability.

Long-Term Security Practices

Implementing network segmentation and access controls can help reduce the impact of adjacent network vulnerabilities like CVE-2023-28981.

Patching and Updates

Juniper has released software updates to address this vulnerability. It is recommended to upgrade Junos OS Evolved to version 20.4R3-S6-EVO or later, and Junos OS to versions 20.3R3-S5 or later depending on the affected release.

By applying the necessary patches and following security best practices, organizations can safeguard their systems against potential DoS attacks exploiting CVE-2023-28981.