CVE-2021-0289 – Junos OS: User-defined ARP Policer isn't applied on Aggregated Ethernet (AE) interface until firewall process is restarted

https://notcve.org/view.php?id=CVE-2021-0289

15 Jul 2021 — When user-defined ARP Policer is configured and applied on one or more Aggregated Ethernet (AE) interface units, a Time-of-check Time-of-use (TOCTOU) Race Condition vulnerability between the Device Control Daemon (DCD) and firewall process (dfwd) daemons of Juniper Networks Junos OS allows an attacker to bypass the user-defined ARP Policer. In this particular case the User ARP policer is replaced with default ARP policer. To review the desired ARP Policers and actual state one can run the command "show inte... • https://kb.juniper.net/JSA11191 • CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition •