title: Junos OS: MX Series with MPC11: In a GNF / node slicing scenario gathering AF interface statistics can lead to a kernel crash
description: A Use After Free vulnerability in the Advanced Forwarding Toolkit (AFT) manager process (aftmand) of Juniper Networks Junos OS allows an unauthenticated networked attacker to cause a kernel crash due to intensive polling of Abstracted Fabric (AF) interface statistics and thereby a Denial of Service (DoS). Continued gathering of AF interface statistics will create a sustained Denial of Service (DoS) condition. This issue affects Juniper Networks Junos OS on MX Series: 20.1 versions later than 20.1R1; 20.2 versions prior to 20.2R3-S5; 20.3 versions prior to 20.3R3-S4; 20.4 versions prior to 20.4R3; 21.1 versions prior to 21.1R2; 21.2 versions prior to 21.2R2.
problem types: CWE-416 Use After Free
affected:
{
platforms: MX Series
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 20.1*, status: affected, version: 20.1R1, versionType: custom
lessThan: 20.2R3-S5, status: affected, version: 20.2, versionType: custom
lessThan: 20.3R3-S4, status: affected, version: 20.3, versionType: custom
lessThan: 20.4R3, status: affected, version: 20.4, versionType: custom
lessThan: 21.1R2, status: affected, version: 21.1, versionType: custom
lessThan: 21.2R2, status: affected, version: 21.2, versionType: custom
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: HIGH
baseScore: 7.5
baseSeverity: HIGH
confidentialityImpact: NONE
integrityImpact: NONE
privilegesRequired: NONE
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/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 Junos OS software releases have been updated to resolve this specific issue Junos OS: 20.2R3-S5, 20.3R3-S4, 20.4R3, 21.1R2, 21.2R2, 21.3R1, and all subsequent releases.
workarounds: There are no viable workarounds for this issue.
To reduce the risk of exploitation of this issue, use access lists or firewall filters to limit access to only trusted networks, hosts and users.