title: Junos OS: MX Series: Gathering statistics in a scaled SCU/DCU configuration will lead to a device crash
description:
An Improper Check for Unusual or Exceptional Conditions vulnerability in the kernel of Juniper Network Junos OS on MX Series allows a network based attacker with low privileges to cause a denial of service.
If a scaled configuration for Source class usage (SCU) / destination class usage (DCU) (more than 10 route classes) is present and the SCU/DCU statistics are gathered by executing specific SNMP requests or CLI commands, a 'vmcore' for the RE kernel will be seen which leads to a device restart. Continued exploitation of this issue will lead to a sustained DoS.
This issue only affects MX Series devices with MPC10, MPC11 or LC9600, and MX304. No other MX Series devices are affected.
This issue affects Juniper Networks Junos OS:
*  All versions earlier than 20.4R3-S9;
*  21.2 versions earlier than 21.2R3-S6;
*  21.3 versions earlier than 21.3R3-S5;
*  21.4 versions earlier than 21.4R3;
*  22.1 versions earlier than 22.1R3;
*  22.2 versions earlier than 22.2R2;
*  22.3 versions earlier than 22.3R2.
problem types: CWE-754 Improper Check for Unusual or Exceptional Conditions
affected:
{
defaultStatus: unaffected
platforms: MX Series
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 20.4R3-S9, status: affected, version: 0, versionType: semver
lessThan: 21.2R3-S6, status: affected, version: 21.2, versionType: semver
lessThan: 21.3R3-S5, status: affected, version: 21.3, versionType: semver
lessThan: 21.4R3, status: affected, version: 21.4, versionType: semver
lessThan: 22.1R3, status: affected, version: 22.1, versionType: semver
lessThan: 22.2R2, status: affected, version: 22.2, versionType: semver
lessThan: 22.3R2, status: affected, version: 22.3, versionType: semver
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: HIGH
baseScore: 6.5
baseSeverity: MEDIUM
confidentialityImpact: NONE
integrityImpact: NONE
privilegesRequired: LOW
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/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-S9, 21.2R3-S6, 21.3R3-S5, 21.4R3, 22.1R3, 22.2R2, 22.3R2, 22.4R1, and all subsequent releases.
workarounds: There are no known workarounds for this issue.