title: Junos OS and Junos OS Evolved: An IS-IS adjacency might be taken down if a bad hello PDU is received for an existing adjacency causing a DoS
description: A Protection Mechanism Failure vulnerability in RPD (routing protocol daemon) 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 receipted of these spoofed PDUs will create a sustained Denial of Service (DoS) condition. This issue affects: Juniper Networks Junos OS All versions prior to 18.2R3-S8; 18.3 versions prior to 18.3R3-S5; 18.4 versions prior to 18.4R3-S9; 19.1 versions prior to 19.1R3-S7; 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 19.4R3-S3; 20.1 versions prior to 20.1R3; 20.2 versions prior to 20.2R3; 20.3 versions prior to 20.3R3; 20.4 versions prior to 20.4R2. Juniper Networks Junos OS Evolved All versions prior to 20.4R2-EVO; 21.1 versions prior to 21.1R2-EVO.
problem types: CWE-693 Protection Mechanism Failure
affected:
{
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 18.2R3-S8, status: affected, version: unspecified, versionType: custom
lessThan: 18.3R3-S5, status: affected, version: 18.3, versionType: custom
lessThan: 18.4R3-S9, status: affected, version: 18.4, versionType: custom
lessThan: 19.1R3-S7, status: affected, version: 19.1, versionType: custom
lessThan: 19.2R1-S7, 19.2R3-S3, status: affected, version: 19.2, versionType: custom
lessThan: 19.3R2-S6, 19.3R3-S2, status: affected, version: 19.3, versionType: custom
lessThan: 19.4R3-S3, status: affected, version: 19.4, versionType: custom
lessThan: 20.1R3, status: affected, version: 20.1, versionType: custom
lessThan: 20.2R3, status: affected, version: 20.2, versionType: custom
lessThan: 20.3R3, status: affected, version: 20.3, versionType: custom
lessThan: 20.4R2, status: affected, version: 20.4, versionType: custom
}
{
product: Junos OS Evolved
vendor: Juniper Networks
versions:
lessThan: 20.4R2-EVO, status: affected, version: unspecified, versionType: custom
lessThan: 21.1R2-EVO, status: affected, version: 21.1, versionType: custom
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: ADJACENT_NETWORK
availabilityImpact: HIGH
baseScore: 6.5
baseSeverity: MEDIUM
confidentialityImpact: NONE
integrityImpact: NONE
privilegesRequired: NONE
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
version: 3.1
]
exploits: Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
solutions: The following software releases have been updated to resolve this specific issue in JUNOS OS: 18.2R3-S8, 18.3R3-S5, 18.4R3-S9, 19.1R3-S7, 19.2R1-S7, 19.2R3-S3, 19.3R2-S6, 19.3R3-S2, 19.4R3-S3, 20.1R3, 20.2R3, 20.3R3, 20.4R2, 21.1R1, and all subsequent releases.
The following software releases have been updated to resolve this specific issue in JUNOS OS Evolved: 20.4R2-EVO, 21.1R2-EVO, 21.2R1-EVO, and all subsequent releases.
workarounds: There are no viable workarounds for this issue.