title: SRX Series: A remote attacker may cause a high CPU Denial of Service to the device when proxy ARP is configured.
description: A firewall bypass vulnerability in the proxy ARP service of Juniper Networks Junos OS allows an attacker to cause a high CPU condition leading to a Denial of Service (DoS). This issue affects only IPv4. Affected releases are Juniper Networks Junos OS: 12.1X46 versions above and including 12.1X46-D25 prior to 12.1X46-D71, 12.1X46-D73 on SRX Series; 12.3X48 versions prior to 12.3X48-D50 on SRX Series; 15.1X49 versions prior to 15.1X49-D75 on SRX Series.
problem types: CWE-400 Uncontrolled Resource Consumption
affected:
{
platforms: SRX Series
product: Junos OS
vendor: Juniper Networks
versions:
changes: [at: 12.1X46-D71, 12.1X46-D73, status: unaffected], lessThan: 12.1X46*, status: affected, version: 12.1X46-D25, versionType: custom
lessThan: 12.3X48-D50, status: affected, version: 12.3X48, versionType: custom
lessThan: 15.1X49-D75, status: affected, version: 15.1X49, versionType: custom
}
metrics:
cvssV3_0: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: HIGH
baseScore: 7.5
baseSeverity: HIGH
confidentialityImpact: NONE
integrityImpact: NONE
privilegesRequired: NONE
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
version: 3.0
]
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: 12.1X46-D71, 12.1X46-D73, 12.3X48-D50, 15.1X49-D75, 17.3R1, and all subsequent releases.
workarounds: Discontinue use of proxy ARP.
An example configuration snippet is below:
deactivate security nat proxy-arp interface ge-0/0/0.0 address 2.2.2.5/32
(or)
delete security nat proxy-arp interface ge-0/0/0.0 address 2.2.2.5/32
There are no other viable workarounds for this issue.