title: Junos OS: MX Series: An FPC crash is observed when CFM is enabled in a VPLS scenario and a specific LDP related command is run
description:
An Improper Release of Memory Before Removing Last Reference vulnerability in Packet Forwarding Engine (PFE) of Juniper Networks Junos OS allows a local, low privileged attacker to cause an FPC crash, leading to Denial of Service (DoS).
On all Junos MX Series with MPC1 - MPC9, LC480, LC2101, MX10003, and MX80, when Connectivity-Fault-Management (CFM) is enabled in a VPLS scenario, and a specific LDP related command is run, an FPC will crash and reboot. Continued execution of this specific LDP command can lead to sustained Denial of Service condition.
This issue affects:
Juniper Networks Junos OS on MX Series:
*  All versions prior to 20.4R3-S7;
*  21.1 versions prior to 21.1R3-S5;
*  21.2 versions prior to 21.2R3-S4;
*  21.3 versions prior to 21.3R3-S4;
*  21.4 versions prior to 21.4R3-S3;
*  22.1 versions prior to 22.1R3-S1;
*  22.2 versions prior to 22.2R2-S1, 22.2R3;
*  22.3 versions prior to 22.3R1-S2, 22.3R2.
problem types: CWE-401 Improper Release of Memory Before Removing Last Reference
affected:
{
defaultStatus: unaffected
platforms: MX Series
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 20.4R3-S7, status: affected, version: 0, versionType: semver
lessThan: 21.1R3-S5, status: affected, version: 21.1, versionType: semver
lessThan: 21.2R3-S4, status: affected, version: 21.2, versionType: semver
lessThan: 21.3R3-S4, status: affected, version: 21.3, versionType: semver
lessThan: 21.4R3-S3, status: affected, version: 21.4, versionType: semver
lessThan: 22.1R3-S1, status: affected, version: 22.1, versionType: semver
lessThan: 22.2R2-S1, 22.2R3, status: affected, version: 22.2, versionType: semver
lessThan: 22.3R1-S2, 22.3R2, status: affected, version: 22.3, versionType: semver
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: LOCAL
availabilityImpact: HIGH
baseScore: 5.5
baseSeverity: MEDIUM
confidentialityImpact: NONE
integrityImpact: NONE
privilegesRequired: LOW
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
version: 3.1
]
format: CVSS
scenarios: GENERAL
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: Junos OS 20.4R3-S7, 21.1R3-S5, 21.2R3-S4, 21.3R3-S4, 21.4R3-S3, 22.1R3-S1, 22.2R2-S1, 22.2R3, 22.3R1-S2, 22.3R2, 22.4R1, and all subsequent releases.
workarounds: This issue can be avoided by disabling CFM MIP functionality.
[ protocols oam ethernet connectivity-fault-management maintenance-domain mip-half-function none ]