CVE-2021-0264

Name of the Vulnerable Software and Affected Versions Junos OS versions prior to 19.3R3-S2 Junos OS versions prior to 19.4R3-S2 Junos OS versions prior to 20.1R3 Junos OS versions prior to 20.2R2-S2 Junos OS versions prior to 20.2R3 Junos OS versions prior to 20.3R3 Junos OS versions prior to 20.4R2 Junos OS Evolved on PTX10003, PTX10008 versions prior to 20.4R2-EVO

Description The issue is related to the incorrect handling of exceptional states in the configuration of firewall filters in Junos OS on certain devices, including MX Series and PTX10003 and PTX10008 Series devices. This can be exploited by a remote attacker to cause a denial of service. When traffic matches a firewall filter containing a syslog action, the line card may crash and restart, impacting traffic processing.

Recommendations For Junos OS versions prior to 19.3R3-S2, update to 19.3R3-S2 or later. For Junos OS versions prior to 19.4R3-S2, update to 19.4R3-S2 or later. For Junos OS versions prior to 20.1R3, update to 20.1R3 or later. For Junos OS versions prior to 20.2R2-S2, update to 20.2R2-S2 or later. For Junos OS versions prior to 20.2R3, update to 20.2R3 or later. For Junos OS versions prior to 20.3R3, update to 20.3R3 or later. For Junos OS versions prior to 20.4R2, update to 20.4R2 or later. For Junos OS Evolved on PTX10003, PTX10008 versions prior to 20.4R2-EVO, update to 20.4R2-EVO or later. As a temporary workaround, consider restricting access to the firewall filter configuration to minimize the risk of exploitation.