An Origin Validation vulnerability in MAC address validation of Juniper Networks Junos OS Evolved on PTX10003 Series allows a network-adjacent attacker to bypass MAC address checking, allowing MAC addresses not intended to reach the adjacent LAN to be forwarded to the downstream network. Due to this issue, the router will start forwarding traffic if a valid route is present in forwarding-table, causing a loop and congestion in the downstream layer-2 domain connected to the device.
 

This issue affects Juniper Networks Junos OS Evolved on PTX10003 Series:

• All versions prior to 21.4R3-S4-EVO;
• 22.1 versions prior to 22.1R3-S3-EVO;
• 22.2 version 22.2R1-EVO and later versions;
• 22.3 versions prior to 22.3R2-S2-EVO, 22.3R3-S1-EVO;
• 22.4 versions prior to 22.4R2-S1-EVO, 22.4R3-EVO;
• 23.2 versions prior to 23.2R2-EVO.

No specific configuration is required.

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-2023-44189.

The following software releases have been updated to resolve this specific issue: Junos OS Evolved 21.4R3-S4-EVO, 22.1R3-S3-EVO, 22.3R2-S2-EVO, 22.3R3-S1-EVO, 22.4R2-S1-EVO, 22.4R3-EVO, 23.2R2-EVO, 23.3R1-EVO, and all subsequent releases.
 

This issue is being tracked as PR 1732283 which is visible on the Customer Support website.

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

2023-10-11: 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-2023-44189 at cve.mitre.org
• https://supportportal.juniper.net/JSA73153 [juniper.net]