CVE-2022-0028
PAN-OS: Reflected Amplification Denial-of-Service (DoS) Vulnerability in URL Filtering
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
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.
Official description from the CVE record, published by palo_alto. Copyright © 1999-2026 The MITRE Corporation. See /security/cve/legal for the CVE license. View the record on cve.org
Key data
CVSS 3.1 High 8.6
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Attack vector: Network
The vulnerable component can be reached over a network, possibly from the Internet.
Attack complexity: Low
No special conditions are needed. The attack can be repeated at will.
Privileges required: None
No account or privileges are needed.
User interaction: None
No action from any user is needed.
Scope: Changed
The impact can reach other components beyond the vulnerable one.
Confidentiality impact: None
No effect on the secrecy of data.
Integrity impact: None
No effect on the trustworthiness of data.
Availability impact: High
Serious or total effect on availability.
| Metric | Value | What it means |
|---|---|---|
| Attack vector | Network | The vulnerable component can be reached over a network, possibly from the Internet. |
| Attack complexity | Low | No special conditions are needed. The attack can be repeated at will. |
| Privileges required | None | No account or privileges are needed. |
| User interaction | None | No action from any user is needed. |
| Scope | Changed | The impact can reach other components beyond the vulnerable one. |
| Confidentiality impact | None | No effect on the secrecy of data. |
| Integrity impact | None | No effect on the trustworthiness of data. |
| Availability impact | High | Serious or total effect on availability. |
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EPSS
- Score
- 0.02690 (2.7% probability)
- Percentile
- 86.0%
- Scores of
- Nov 10, 2026
- Model
- v2026.06.15
CISA Known Exploited Vulnerabilities
- Name in the catalog
- Palo Alto Networks PAN-OS Reflected Amplification Denial-of-Service Vulnerability
- Added to the catalog
- Aug 22, 2022
- Federal due date
- Sep 12, 2022
CISA assessment as of Jan 27, 2025
- Exploitation
- Recorded by CISA as active
- Automatable
- yes
- Technical impact
- partial
Weakness (CWE)
- CWE-406Insufficient Control of Network Message Volume (Network Amplification)
Affected products
Palo Alto Networks Cloud NGFW
- unaffected: All
Palo Alto Networks PAN-OS
- affected: 8.1 up to before 8.1.23-h1
- affected: 9.0 up to before 9.0.16-h3
- affected: 9.1 up to before 9.1.14-h4
- affected: 10.0 up to before 10.0.11-h1
- affected: 10.1 up to before 10.1.6-h6
- affected: 10.2 up to before 10.2.2-h2
Palo Alto Networks Prisma Access
- unaffected: 2.1 All
- unaffected: 2.2 All
- unaffected: 3.0 All
- unaffected: 3.1 All
References
Timeline
- ID reserved
- Record published
- Added to CISA KEV
- Record last updated
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Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:27 UTC. Sources and licenses