CVE-2022-0028: Palo Alto Networks PAN-OS Reflected Amplification Denial-of-Service Vulnerability

High severity, CVSS 8.6. Actively exploited: in CISA KEV since 2022-08-22. EPSS: 2.5% chance of exploitation in the next 30 days.

A PAN-OS URL filtering policy misconfiguration could allow a network-based attacker to conduct reflected and amplified TCP denial-of-service (RDoS) attacks. The DoS attack would appear to originate from a Palo Alto Networks PA-Series (hardware), VM-Series (virtual) and CN-Series (container) firewall against an attacker-specified target. To be misused by an external attacker, the firewall configuration must have a URL filtering profile with one or more blocked categories assigned to a source zone that has an external facing interface. This configuration is not typical for URL filtering and, if set, is likely unintended by the administrator. If exploited, this issue would not impact the confidentiality, integrity, or availability of our products. However, the resulting denial-of-service (DoS) attack may help obfuscate the identity of the attacker and implicate the firewall as the source of the attack. We have taken prompt action to address this issue in our PAN-OS software. All software updates for this issue are expected to be released no later than the week of August 15, 2022. This issue does not impact Panorama M-Series or Panorama virtual appliances. This issue has been resolved for all Cloud NGFW and Prisma Access customers and no additional action is required from them.

Affected products

• Palo Alto Networks PAN-OS: from 8.1.0, before 8.1.23 (fixed in 8.1.23); from 9.0.0, before 9.0.16 (fixed in 9.0.16); from 9.1.0, before 9.1.14 (fixed in 9.1.14); from 10.0.0, before 10.0.11 (fixed in 10.0.11); from 10.1.0, before 10.1.6 (fixed in 10.1.6); from 10.2.0, before 10.2.2 (fixed in 10.2.2); …

Published 2022-08-10. Last modified 2026-06-17.