title: Junos OS: QFX5000 Series and MX Series: An l2alm crash leading to an FPC crash can be observed in VxLAN scenario
description: A NULL Pointer Dereference vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on QFX5000 Series and MX Series allows an unauthenticated adjacent attacker to cause a Denial of Service (DoS). On QFX5K Series and MX Series, when the PFE receives a specific VxLAN packet the Layer 2 Address Learning Manager (L2ALM) process will crash leading to an FPC reboot. Continued receipt of this specific packet will create a sustained Denial of Service (DoS) condition. This issue affects Juniper Networks Junos OS on QFX5000 Series, MX Series: 20.3 versions prior to 20.3R3-S3; 20.4 versions prior to 20.4R3-S2; 21.2 versions prior to 21.2R2-S1. This issue does not affect Juniper Networks Junos OS: All versions prior to 20.3R1; 21.1 version 21.1R1 and later versions.
problem types: CWE-476 NULL Pointer Dereference
affected:
{
platforms: QFX5000 Series, MX Series
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 20.3R3-S3, status: affected, version: 20.3, versionType: custom
lessThan: 20.4R3-S2, status: affected, version: 20.4, versionType: custom
lessThan: 21.2R2-S1, status: affected, version: 21.2, versionType: custom
}
{
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 20.3R1, status: unaffected, version: unspecified, versionType: custom
lessThan: 21.1*, status: unaffected, version: 21.1R1, 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: 20.3R3-S3, 20.4R3-S2, 21.2R2-S1, and all subsequent releases.
workarounds: There are no viable workarounds for this issue.