An Incorrect Behavior Order in the routing engine (RE) of Juniper Networks Junos OS on EX4300 Series allows traffic intended to the device to reach the RE instead of being discarded when the discard term is set in loopback (lo0) interface. The intended function is that the lo0 firewall filter takes precedence over the revenue interface (ex. ge-0/0/0) firewall filter. 

This issue only affects IPv6 firewall filter.

This issue only affects the EX4300 switch. No other products or platforms are affected by this vulnerability. 

This issue affects Juniper Networks Junos OS on EX4300:

• All versions before 20.4R3-S10,
• from 21.2 before 21.2R3-S7,
• from 21.4 before 21.4R3-S6.

This issue affects Junos OS device with IPv6 firewall filter configured for both lo0 interface and revenue interface (ex- ge-0/0/0):

 [firewall family inet6 filter]

The following software releases have been updated to resolve this specific issue: Junos OS: 20.4R3-S10, 21.2R3-S7, 21.4R3-S6, and all subsequent releases.
 

This issue is being tracked as 1775558 which is visible on the Customer Support website.
 

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

• 2024-04-10 - Initial Publication
• 2024-09-13: Minor formatting change to CVSS field

• 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
• https://www.cve.org/CVERecord?id=CVE-2024-30410