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 firewall filter. This issue affects only 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: * All versions before 20.4R3-S10, * from 21.2 before 21.2R3-S7, * from 21.4 before 21.4R3-S6.
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.
When lo0 filter is applied before the revenue interface (ex. ge-0/0/0) filter this issue could be avoided.
| Product | Vulnerable range | Fixed version | Advisory |
|---|---|---|---|
| Juniper Networks Junos | <20.4R3-S10 | 20.4R3-S10 | advisory ↗ |
| Juniper Networks Junos | >=21.2<21.2R3-S7 | 21.2R3-S7 | advisory ↗ |
| Juniper Networks Junos | >=21.4<21.4R3-S6 | 21.4R3-S6 | advisory ↗ |