title: Junos OS Evolved: A remote attacker may cause a CPU Denial of Service by sending genuine traffic to a device on a specific IPv4 port.
description: An Improper Access Control vulnerability in Juniper Networks Junos OS Evolved allows a network-based unauthenticated attacker who is able to connect to a specific open IPv4 port, which in affected releases should otherwise be unreachable, to cause the CPU to consume all resources as more traffic is sent to the port to create a Denial of Service (DoS) condition. Continued receipt and processing of these packets will create a sustained Denial of Service (DoS) condition. This issue affects: Juniper Networks Junos OS Evolved 20.4 versions prior to 20.4R3-S2-EVO; 21.1 versions prior to 21.1R3-S1-EVO; 21.2 versions prior to 21.2R3-EVO; 21.3 versions prior to 21.3R2-EVO; 21.4 versions prior to 21.4R2-EVO. This issue does not affect Junos OS.
problem types: Denial of Service (DoS)
affected:
{
product: Junos OS Evolved
vendor: Juniper Networks
versions:
lessThan: 20.4R3-S2-EVO, status: affected, version: 20.4, versionType: custom
lessThan: 21.1R3-S1-EVO, status: affected, version: 21.1, versionType: custom
lessThan: 21.2R3-EVO, status: affected, version: 21.2, versionType: custom
lessThan: 21.3R2-EVO, status: affected, version: 21.3, versionType: custom
lessThan: 21.4R2-EVO, status: affected, version: 21.4, versionType: custom
}
{
product: Junos OS
vendor: Juniper Networks
versions:
status: unaffected, version: Any
}
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 software releases have been updated to resolve this specific issue: 20.4R3-S2-EVO, 21.1R3-S1-EVO, 21.2R3-EVO, 21.3R2-EVO, 21.4R2-EVO, 22.1R1-EVO, and all subsequent releases.
workarounds: There are no available workarounds for this issue.
To reduce the risk of exploitation customers may enable loopback firewall filters on the device to drop unnecessary connections and traffic from untrusted networks and devices.