Junos OS: MX104 might become unresponsive if the out-of-band management port receives a flood of traffic

Vulnerability Description

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 an irq handled by the fman process is shown to be using a high percentage of CPU cycles like in the following example output: user@host> show system processes extensive ... PID USERNAME PRI NICE SIZE RES STATE TIME WCPU COMMAND 31 root -84 -187 0K 16K WAIT 22.2H 56939.26% irq96: fman0 This issue affects Juniper Networks Junos OS: All versions prior to 18.3R3-S6; 18.4 versions prior to 18.4R2-S9, 18.4R3-S9; 19.1 versions prior to 19.1R2-S3, 19.1R3-S7; 19.2 versions prior to 19.2R1-S7, 19.2R3-S3; 19.3 versions prior to 19.3R2-S7, 19.3R3-S4; 19.4 versions prior to 19.4R2-S5, 19.4R3-S5; 20.1 versions prior to 20.1R3-S1; 20.2 versions prior to 20.2R3-S2; 20.3 versions prior to 20.3R3-S1; 20.4 versions prior to 20.4R2-S2, 20.4R3; 21.1 versions prior to 21.1R2; 21.2 versions prior to 21.2R1-S1, 21.2R2.

References

• https://kb.juniper.net/JSA11269