A Use After Free vulnerability in the kernel of Juniper Networks Junos OS Evolved allows an unauthenticated, network-based attacker to cause a Denial of Service (DoS).

In a Non Stop Routing (NSR) scenario, an unexpected kernel restart might be observed if "bgp auto-discovery" is enabled and if there is a BGP neighbor flap of auto-discovery sessions for any reason. This is a race condition which is outside of an attackers direct control and it depends on system internal timing whether this issue occurs.

This issue affects Juniper Networks Junos OS Evolved:

• 21.3 versions prior to 21.3R3-EVO;
• 21.4 versions prior to 21.4R2-EVO;
• 22.1 versions prior to 22.1R2-EVO;
• 22.2 versions prior to 22.2R1-S1-EVO, 22.2R2-EVO.

To be exposed to this is issue non-stop routing (NSR) and BGP auto-discovery need to be configured:

Juniper SIRT is not aware of any malicious exploitation of this vulnerability.

This issue was seen during production usage.

This issue has been assigned CVE-2023-22402.

The following software releases have been updated to resolve this specific issue: 21.3R3-EVO, 21.4R2-EVO, 22.1R2-EVO, 22.2R1-S1-EVO, 22.2R2-EVO, 22.3R1-EVO, and all subsequent releases.

This issue is being tracked as 1636063.

Note: Juniper SIRT's policy is not to evaluate releases which are beyond End of Engineering (EOE) or End of Life (EOL).

• 2023-01-11: Initial Publication

• KB16613: Overview of the Juniper Networks SIRT Quarterly Security Bulletin Publication Process [juniper.net]
• KB16765: In which releases are vulnerabilities fixed? [juniper.net]
• KB16446: Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories [juniper.net]
• Report a Security Vulnerability - How to Contact the Juniper Networks Security Incident Response Team
• CVE-2023-22402 at cve.mitre.org