Junos CVE-2021-31368

This vulnerability is classified as Uncontrolled Resource Consumption (CWE-400), which allows attackers to cause denial of service by exhausting system resources. An Uncontrolled Resource Consumption vulnerability in the kernel of Juniper Networks JUNOS OS allows an unauthenticated network based attacker to cause 100% CPU load and the device to become unresponsive by sending a flood of traffic to the out-of-band management ethernet port. Continued receipted of a flood will create a sustained Denial of Service (DoS) condition. Once the flood subsides the system will recover by itself. An indication that the system is affected by this issue would be that kernel and netisr process are shown to be using a lot of CPU cycles like in the following example output: user@host> show system processes extensive ... PID USERNAME PRI NICE SIZE RES STATE C TIME WCPU COMMAND 16 root -72 - 0K 304K WAIT 1 839:40 88.96% intr{swi1: netisr 0} 0 root 97 - 0K 160K RUN 1 732:43 87.99% kernel{bcm560xgmac0 que}1R3-S13; 18.2 versions prior to 18.2R3-S8; 18.3 versions prior to 18.3R3-S5; 18.4 versions prior to 18.4R2-S8, 18.4R3-S9; 19.1 versions prior to 19.1R3-S5; 19.2 versions prior to 19.2R1-S7, 19.2R3-S3; 19.3 versions prior to 19.3R2-S6, 19.3R3-S2; 19.4 versions prior to 19.4R1-S4, 19.4R3-S3; 20.1 versions prior to 20.1R2-S2, 20.1R3; 20.2 versions prior to 20.2R3; 20.3 versions prior to 20.3R2-S1, 20.3R3; 20.4 versions prior to 20.4R2. Affected products include: Juniper Junos. Version information: prior to 18.1.