PT-2021-19261 · Juniper Networks · Junos Evolved+1

Published 2021-10-19 · Updated 2021-10-25 · CVE-2021-31362

Positive Technologies (AI Summary)

CVSS v3.1

6.5

Medium

Base vector

AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions Juniper Networks Junos OS versions prior to 18.2R3-S8 Juniper Networks Junos OS versions 18.3 prior to 18.3R3-S5 Juniper Networks Junos OS versions 18.4 prior to 18.4R3-S9 Juniper Networks Junos OS versions 19.1 prior to 19.1R3-S7 Juniper Networks Junos OS versions 19.2 prior to 19.2R1-S7 Juniper Networks Junos OS versions 19.2 prior to 19.2R3-S3 Juniper Networks Junos OS versions 19.3 prior to 19.3R2-S6 Juniper Networks Junos OS versions 19.3 prior to 19.3R3-S2 Juniper Networks Junos OS versions 19.4 prior to 19.4R3-S3 Juniper Networks Junos OS versions 20.1 prior to 20.1R3 Juniper Networks Junos OS versions 20.2 prior to 20.2R3 Juniper Networks Junos OS versions 20.3 prior to 20.3R3 Juniper Networks Junos OS versions 20.4 prior to 20.4R2 Juniper Networks Junos OS Evolved versions prior to 20.4R2-EVO Juniper Networks Junos OS Evolved versions 21.1 prior to 21.1R2-EVO

Description A Protection Mechanism Failure issue in the RPD of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent unauthenticated attacker to cause established IS-IS adjacencies to go down by sending a spoofed hello PDU, leading to a Denial of Service (DoS) condition. Continued receipt of these spoofed PDUs will create a sustained Denial of Service (DoS) condition.

Recommendations For Juniper Networks Junos OS versions prior to 18.2R3-S8, update to version 18.2R3-S8 or later. For Juniper Networks Junos OS versions 18.3 prior to 18.3R3-S5, update to version 18.3R3-S5 or later. For Juniper Networks Junos OS versions 18.4 prior to 18.4R3-S9, update to version 18.4R3-S9 or later. For Juniper Networks Junos OS versions 19.1 prior to 19.1R3-S7, update to version 19.1R3-S7 or later. For Juniper Networks Junos OS versions 19.2 prior to 19.2R1-S7, update to version 19.2R1-S7 or later. For Juniper Networks Junos OS versions 19.2 prior to 19.2R3-S3, update to version 19.2R3-S3 or later. For Juniper Networks Junos OS versions 19.3 prior to 19.3R2-S6, update to version 19.3R2-S6 or later. For Juniper Networks Junos OS versions 19.3 prior to 19.3R3-S2, update to version 19.3R3-S2 or later. For Juniper Networks Junos OS versions 19.4 prior to 19.4R3-S3, update to version 19.4R3-S3 or later. For Juniper Networks Junos OS versions 20.1 prior to 20.1R3, update to version 20.1R3 or later. For Juniper Networks Junos OS versions 20.2 prior to 20.2R3, update to version 20.2R3 or later. For Juniper Networks Junos OS versions 20.3 prior to 20.3R3, update to version 20.3R3 or later. For Juniper Networks Junos OS versions 20.4 prior to 20.4R2, update to version 20.4R2 or later. For Juniper Networks Junos OS Evolved versions prior to 20.4R2-EVO, update to version 20.4R2-EVO or later. For Juniper Networks Junos OS Evolved versions 21.1 prior to 21.1R2-EVO, update to version 21.1R2-EVO or later.

Fix

DoS

Protection Mechanism Failure

Weakness Enumeration

CWE-693

Related Identifiers

CVE-2021-31362

Affected Products

Junos

Junos Evolved

References · 3

• https://osv.dev/vulnerability/CVE-2021-31362 · Vendor Advisory
• https://kb.juniper.net/JSA11224 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-31362 · Security Note