CVE-2021-3063Network attack vector

Device reboot via crafted GlobalProtect traffic

Published Nov 10, 2021 · Updated Sep 16, 2024

Improper exceptional-condition handling in Palo Alto Networks PAN-OS allows remote attackers to restart affected firewalls. The GlobalProtect portal and gateway interfaces fail to handle specifically crafted network traffic, causing their service to stop responding. Exposure requires an enabled, network-reachable GlobalProtect portal or gateway on PAN-OS 8.1 before 8.1.21, 9.0 before 9.0.14-h4, 9.1 before 9.1.11-h3, 10.0 before 10.0.8-h4, or 10.1 before 10.1.3; repeated requests can interrupt all PAN-OS services.

CVSS severity7.5
High
EPSS probability0.93%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper exceptional-condition handling in Palo Alto Networks PAN-OS allows remote attackers to restart affected firewalls. The GlobalProtect portal and gateway interfaces fail to handle specifically crafted network traffic, causing their service to stop responding. Exposure requires an enabled, network-reachable GlobalProtect portal or gateway on PAN-OS 8.1 before 8.1.21, 9.0 before 9.0.14-h4, 9.1 before 9.1.11-h3, 10.0 before 10.0.8-h4, or 10.1 before 10.1.3; repeated requests can interrupt all PAN-OS services.

The record

CVE
CVE-2021-3063
Published
Nov 10, 2021
Updated
Sep 16, 2024
Vendor
Palo Alto Networks
Product
PAN-OS
Classifications
CWE-755, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 10, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10.0 <10.0.8-h4 changes=[{"at":"10.0.8-h4","status":"unaffected"}]
  2. Affected versionversion=10.1 <10.1.3 changes=[{"at":"10.1.3","status":"unaffected"}]
  3. Affected versionversion=8.1 <8.1.21 changes=[{"at":"8.1.21","status":"unaffected"}]
  4. Affected versionversion=9.0 <9.0.14-h4 changes=[{"at":"9.0.14-h4","status":"unaffected"}]
  5. Affected versionversion=9.1 <9.1.11-h3 changes=[{"at":"9.1.11-h3","status":"unaffected"}]

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Palo Alto Networks · PAN-OSversion=10.0 <10.0.8-h4 changes=[{"at":"10.0.8-h4","status":"unaffected"}]; version=10.1 <10.1.3 changes=[{"at":"10.1.3","status":"unaffected"}]; version=8.1 <8.1.21 changes=[{"at":"8.1.21","status":"unaffected"}]; version=9.0 <9.0.14-h4 changes=[{"at":"9.0.14-h4","status":"unaffected"}]; version=9.1 <9.1.11-h3 changes=[{"at":"9.1.11-h3","status":"unaffected"}]

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:N/A:P
7.5Palo Alto Networks, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-755Improper Handling of Exceptional Conditions
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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