CVE-2021-0287

Name of the Vulnerable Software and Affected Versions Juniper Networks Junos OS versions 19.4 through 19.4R1-S4, 19.4R3-S2; 20.1 versions prior to 20.1R2-S1, 20.1R3; 20.2 versions prior to 20.2R2-S2, 20.2R3; 20.3 versions prior to 20.3R2 Juniper Networks Junos OS Evolved versions 20.3-EVO prior to 20.3R2-EVO; 20.4-EVO versions prior to 20.4R2-EVO

Description In a Segment Routing ISIS (SR-ISIS)/MPLS environment, on Juniper Networks Junos OS and Junos OS Evolved devices, configured with ISIS Flexible Algorithm for Segment Routing and sensor-based statistics, a flap of a ISIS link in the network can lead to a routing process daemon (RPD) crash and restart, causing a Denial of Service (DoS). Continued link flaps will create a sustained Denial of Service (DoS) condition.

Recommendations For Juniper Networks Junos OS versions 19.4 through 19.4R1-S4, 19.4R3-S2, update to version 19.4R1-S4 or later. For Juniper Networks Junos OS versions 20.1 prior to 20.1R2-S1, 20.1R3, update to version 20.1R2-S1 or later. For Juniper Networks Junos OS versions 20.2 prior to 20.2R2-S2, 20.2R3, update to version 20.2R2-S2 or later. For Juniper Networks Junos OS versions 20.3 prior to 20.3R2, update to version 20.3R2 or later. For Juniper Networks Junos OS Evolved versions 20.3-EVO prior to 20.3R2-EVO, update to version 20.3R2-EVO or later. For Juniper Networks Junos OS Evolved versions 20.4-EVO prior to 20.4R2-EVO, update to version 20.4R2-EVO or later. As a temporary workaround, consider disabling the ISIS Flexible Algorithm for Segment Routing and sensor-based statistics until a patch is available.