CVE-2019-0033: SRX Series: A remote attacker may cause a high CPU Denial of Service to the device when proxy ARP is configured.

Severity: high (CVSS 7.5 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2019-04-10 · updated 2026-06-17
Weakness: CWE-400

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.

Affected products

Juniper Junos OS: from 12.1x46 through 12.1x46-d10; from 12.1x46-d25 before 12.1x46-d71; from 12.3x48 before 12.3x48-d50; from 15.1x49 before 15.1x49-d75 — fixed in 12.1x46-d71, 12.3x48-d50, 15.1x49-d75

How to fix

Upgrade to a fixed version: Juniper Junos OS 12.1x46-d71, 12.3x48-d50, 15.1x49-d75. Check the vendor advisory for mitigations.

References

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