CVE-2022-0023: CVE-2022-0023 PAN-OS: Denial-of-Service (DoS) Vulnerability in DNS Proxy

Palo Alto Networks Security Advisories / CVE-2022-0023

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Scope UNCHANGED

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

NVD JSON

Published 2022-04-13

Updated 2022-04-13

Reference PAN-164264

Discovered internally

Description

An improper handling of exceptional conditions vulnerability exists in the DNS proxy feature of Palo Alto Networks PAN-OS software that enables a meddler-in-the-middle (MITM) to send specifically crafted traffic to the firewall that causes the service to restart unexpectedly. Repeated attempts to send this request result in denial-of-service to all PAN-OS services by restarting the device in maintenance mode.

This issue does not impact Panorama appliances and Prisma Access customers.

This issue impacts:

PAN-OS 8.1 versions earlier than PAN-OS 8.1.22;

PAN-OS 9.0 versions earlier than PAN-OS 9.0.16;

PAN-OS 9.1 versions earlier than PAN-OS 9.1.13;

PAN-OS 10.0 versions earlier than PAN-OS 10.0.10;

PAN-OS 10.1 versions earlier than PAN-OS 10.1.5.

This issue does not impact PAN-OS 10.2.

Product Status

Versions

Affected

Unaffected

PAN-OS 10.2

None

10.2.*

PAN-OS 10.1

< 10.1.5

>= 10.1.5

PAN-OS 10.0

< 10.0.10

>= 10.0.10

PAN-OS 9.1

< 9.1.13

>= 9.1.13

PAN-OS 9.0

< 9.0.16

>= 9.0.16

PAN-OS 8.1

< 8.1.22

>= 8.1.22

Prisma Access 3.0

None

Preferred, Innovation

Prisma Access 2.2

None

Preferred

Prisma Access 2.1

None

Preferred, Innovation

Required Configuration for Exposure

This issue is applicable only to PAN-OS hardware and virtual firewalls with the DNS proxy feature enabled. You can verify whether DNS proxy is enabled by selecting 'Network > DNS Proxy’ from the web interface.

Severity: MEDIUM

CVSSv3.1 Base Score: 5.9 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H)

Exploitation Status

Palo Alto Networks is not aware of any malicious exploitation of this issue.

Weakness Type

CWE-755 Improper Handling of Exceptional Conditions

Solution

This issue is fixed in PAN-OS 8.1.22, PAN-OS 9.0.16, PAN-OS 9.1.13, PAN-OS 10.0.10, PAN-OS 10.1.5, and all later PAN-OS versions.

Workarounds and Mitigations

Customers with a Threat Prevention subscription can block attack traffic related to this vulnerability by enabling Threat ID 92406 (Applications and Threats content update 8556).

To completely mitigate the risk of this issue, temporarily disable the DNS proxy feature until you are able to upgrade your PAN-OS software to a fixed version.

Acknowledgments

This issue was found by Nicholas Newsom of Palo Alto Networks during internal security review.

Timeline

2022-04-13 Initial publication