PAN-OS: Authentication Bypass with Cloud Authentication Service (CAS) enabled

Overview

An authentication bypass vulnerability in Palo Alto Networks PAN-OS® software enables an unauthenticated attacker with network access to bypass authentication controls when Cloud Authentication Service (CAS) is enabled.

The risk is higher if CAS is enabled on the management interface and lower when any other login interfaces are used.

The risk of this issue is greatly reduced if you secure access to the management web interface by restricting access to only trusted internal IP addresses according to our recommended best practice deployment guidelines https://live.paloaltonetworks.com/t5/community-blogs/tips-amp-tricks-how-to-secure-the-management-access-of-your-palo/ba-p/464431 .

This issue is applicable to PAN-OS software on PA-Series and VM-Series firewalls and on Panorama (virtual and M-Series).

Cloud NGFW and Prisma Access® are not impacted by this vulnerability.

Affected

• cloud_ngfw
• PAN-OS >= 12.1.0 < 12.1.7, 12.1.4-h5
• PAN-OS >= 11.2.0 < 11.2.12, 11.2.10-h6, 11.2.7-h13, 11.2.4-h17
• PAN-OS >= 11.1.0 < 11.1.15, 11.1.13-h5, 11.1.10-h25, 11.1.7-h6, 11.1.6-h32, 11.1.4-h33
• PAN-OS >= 10.2.0 < 10.2.18-h6, 10.2.16-h7, 10.2.13-h21, 10.2.10-h36, 10.2.7-h34
• prisma_access

Remediation

VERSION MINOR VERSION RANGE SUGGESTED SOLUTION Cloud NGFW No action needed. PAN-OS 12.1 12.1.5 through 12.1.6 Upgrade to 12.1.7 or later. 12.1.2 through 12.1.4-h* Upgrade to 12.1.4-h5 or 12.1.7 or later. PAN-OS 11.2 11.2.11 or later Upgrade to 11.2.12 or later. 11.2.8 through 11.2.10-h* Upgrade to 11.2.10-h6 or 11.2.12 or later. 11.2.5 through 11.2.7-h* Upgrade to 11.2.7-h13 or 11.2.12 or later. 11.2.0 through 11.2.4-h* Upgrade to 11.2.4-h17 or 11.2.12 or later. PAN-OS 11.1 11.1.14 or later Upgrade to 11.1.15 or later. 11.1.11 through 11.1.13-h* Upgrade to 11.1.13-h5 or 11.1.15 or later. 11.1.8 through 11.1.10-h* Upgrade to 11.1.10-h25 or 11.1.15 or later. 11.1.7 through 11.1.7-h* Upgrade to 11.1.7-h6 or 11.1.15 or later. 11.1.5 through 11.1.6-h* Upgrade to 11.1.6-h32 or 11.1.15 or later. 11.1.0 through 11.1.4-h* Upgrade to 11.1.4-h33 or 11.1.15 or later. PAN-OS 10.2 10.2.17 through 10.2.18-h* Upgrade to 10.2.18-h6 or later. 10.2.14 through 10.2.16-h* Upgrade to 10.2.16-h7 or 10.2.18-h6 or later. 10.2.11 through 10.2.13-h* Upgrade to 10.2.13-h21 or 10.2.18-h6 or later. 10.2.8 through 10.2.10-h* Upgrade to 10.2.10-h36 or 10.2.18-h6 or later. 10.2.0 through 10.2.7-h* Upgrade to 10.2.7-h34 or 10.2.18-h6 or later. All older Upgrade to a supported fixed version. unsupported PAN-OS versions Prisma Access No action needed.

Workarounds

The vast majority of firewalls already follow Palo Alto Networks' and industry best practices. However, if you haven’t already, we strongly recommend that you secure access to your management interface according to our best practice deployment guidelines. Specifically, you should restrict access to the management interface to only trusted internal IP addresses to prevent external access from the internet.

Review information about how to secure management access to your Palo Alto Networks firewalls:

• Palo Alto Networks LIVEcommunity article: https://live.paloaltonetworks.com/t5/community-blogs/tips-amp-tricks-how-to-secure-the-management-access-of-your-palo/ba-p/464431
• Palo Alto Networks official and more detailed technical documentation: https://docs.paloaltonetworks.com/best-practices/10-1/administrative-access-best-practices/administrative-access-best-practices/deploy-administrative-access-best-practices

To temporarily mitigate this issue, customers can disable the Cloud Authentication Service (CAS) by changing the associated authentication profile to SAML, RADIUS, or other supported authentication methods.

Customers with a Threat Prevention subscription can block attacks for this vulnerability by enabling Threat ID 510008 from Applications and Threats content version 9100-10044 and later. Threat ID 510008 depends on features present in PAN-OS 11.2 and above.

To ensure the Threat ID provides effective protection against this vulnerability, follow these steps:

• Route incoming traffic for the MGT port through a DP port (https://docs.paloaltonetworks.com/best-practices/10-1/administrative-access-best-practices/administrative-access-best-practices/deploy-administrative-access-best-practices#id59206398-3dab-4b2f-9b4b-7ea500d036ba), e.g., enabling management profile on a DP interface for management access.
• Ensure that vulnerability protection security profile is applied to your GlobalProtect interface (https://live.paloaltonetworks.com/t5/globalprotect-articles/applying-vulnerability-protection-to-globalprotect-interfaces/ta-p/340184).
• Replace the default certificate for Inbound Traffic Management (https://docs.paloaltonetworks.com/best-practices/10-1/administrative-access-best-practices/administrative-access-best-practices/deploy-administrative-access-best-practices#id112f7714-8995-4496-bbf9-781e63dec71c).
• Decrypt inbound traffic to the management interface so the firewall can inspect it (https://docs.paloaltonetworks.com/best-practices/10-1/administrative-access-best-practices/administrative-access-best-practices/deploy-administrative-access-best-practices#idbbd82587-17a2-42b4-9245-d3714e1e13a2).
• Enable Threat Prevention on the inbound traffic to management services.