CVE-2022-0028

Description

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.

Severity scores

Each score is shown as its source gave it. They are not averaged or merged.

• 8.6CVSS 3.1, Highfrom the CNA (palo_alto)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

What to do

• We identified workarounds to prevent the denial-of-service (DoS) attacks that result from this issue in certain Palo Alto Networks firewalls, with this policy configuration We intend to fix this issue for PA-Series, VM-Series and CN-Series firewalls with a fix in the following PAN-OS software releases: PAN-OS 8.1.23-h1 (ETA: week of August 8, 2022), PAN-OS 9.0.16-h3 (ETA: week of August 15, 2022), PAN-OS 9.1.14-h4 (ETA: week of August 15, 2022), PAN-OS 10.0.11-h1 (ETA: week of August 15, 2022), PAN-OS 10.1.6-h6 (ETA: week of August 8, 2022), and PAN-OS 10.2.2-h2 (ETA: week of August 15, 2022). We expect to release all PAN-OS software updates for this issue no later than the week of August 15, 2022.CNA solution statement
• If you have a URL filtering policy with one or more blocked categories assigned to a source zone that has an external facing network interface, removing this configuration will prevent this issue from being exploited by remote attackers to conduct reflected DoS. To prevent denial-of-service (DoS) attacks resulting from this issue from all sources, you can configure your Palo Alto Networks firewalls by enabling one of two zone protection mitigations on all Security zones with an assigned Security policy that includes a URL filtering profile: 1. Packet-based attack protection including both (Packet Based Attack Protection > TCP Drop > TCP SYN with Data) and (Packet Based Attack Protection > TCP Drop > Strip TCP Options > TCP Fast Open); OR 2. Flood protection (Flood Protection > SYN > Action > SYN Cookie) with an activation threshold of 0 connections. NOTES: 1. It is not necessary nor advantageous to apply both the attack and flood protections. 2. (Palo Alto Networks Aporeto software only) You should not enable either of these protections if using Aporeto software; instead, wait for and install a fixed version of PAN-OS software. Packet-Based Attack Protection Workaround (Recommended) Follow the technical documentation to configure packet-based attack protection options for all defined Security zones with URL filtering enabled in the Security profile for that zone: https://docs.paloaltonetworks.com/pan-os/10-2/pan-os-admin/zone-protection-and-dos-protection/configure-zone-CNA workaround statement
• Apply updates per vendor instructions.CISA KEV required action

Historical context and remediation

This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.

No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.

Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.

CNA context is abbreviated; consult the original record for the complete statements.

Read the original CVE record.

Affected products

Timeline

1. 10 Aug 2022 Initial publication
2. 10 Aug 2022 Published
3. 22 Aug 2022 CVE-2022-0028 added to CISA KEV
4. 22 Aug 2022 Added to the CISA KEV catalogue

Weakness

• CWE-406

References

• security.paloaltonetworks.comx_refsource_MISC