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CVE-2021-31368

Junos OS: EX2300 Series, EX3400 Series, and ACX710 might become unresponsive if the out-of-band management port receives a flood of traffic

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 18.1R3-S13, 18.2R3-S8, 18.3R3-S5, 19.1R3-S5, 20.2R3, and 1 more
None on Exploit-DB, Metasploit or GitHub

Summary

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} This issue affects Juniper Networks JUNOS OS on EX2300 Series, EX3400 Series, and ACX710: All versions prior to 18.1R3-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.

Timeline

  1. CVE published
  2. Record last updated

Affected versions

  • Juniper Networks Junos OS

    fixed in 18.1R3-S13; From 18.2 · fixed in 18.2R3-S8; From 18.3 · fixed in 18.3R3-S5; From 19.1 · fixed in 19.1R3-S5; From 20.2 · fixed in 20.2R3; From 20.4 · fixed in 20.4R2

References 1

kb.juniper.net