CVE-2021-3063
PAN-OS: Denial-of-Service (DoS) Vulnerability in GlobalProtect Portal and Gateway Interfaces
An improper handling of exceptional conditions vulnerability exists in Palo Alto Networks GlobalProtect portal and gateway interfaces that enables an unauthenticated network-based attacker to send specifically crafted traffic to a GlobalProtect interface that causes the service to stop responding. Repeated attempts to send this request result in denial of service to all PAN-OS services by restarting the device and putting it into maintenance mode. This issue impacts: PAN-OS 8.1 versions earlier than PAN-OS 8.1.21; PAN-OS 9.0 versions earlier than PAN-OS 9.0.14-h4; PAN-OS 9.1 versions earlier than PAN-OS 9.1.11-h3; PAN-OS 10.0 versions earlier than PAN-OS 10.0.8-h4; PAN-OS 10.1 versions earlier than PAN-OS 10.1.3. Prisma Access customers are not impacted by this issue.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
PAN-OS: Denial-of-Service (DoS) Vulnerability in GlobalProtect Portal and Gateway Interfaces
An improper handling of exceptional conditions vulnerability exists in Palo Alto Networks GlobalProtect portal and gateway interfaces that enables an unauthenticated network-based attacker to send specifically crafted traffic to a GlobalProtect interface that causes the service to stop responding. Repeated attempts to send this request result in denial of service to all PAN-OS services by restarting the device and putting it into maintenance mode. This issue impacts: PAN-OS 8.1 versions earlier than PAN-OS 8.1.21; PAN-OS 9.0 versions earlier than PAN-OS 9.0.14-h4; PAN-OS 9.1 versions earlier than PAN-OS 9.1.11-h3; PAN-OS 10.0 versions earlier than PAN-OS 10.0.8-h4; PAN-OS 10.1 versions earlier than PAN-OS 10.1.3. Prisma Access customers are not impacted by this issue.
- Record
CVE-2021-3063- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-755
- Updated
- 2026-11-02
EUVDEUVD-2021-26415
An improper handling of exceptional conditions vulnerability exists in Palo Alto Networks GlobalProtect portal and gateway interfaces that enables an unauthenticated network-based attacker to send specifically crafted traffic to a GlobalProtect interface that causes the service to stop responding. Repeated attempts to send this request result in denial of service to all PAN-OS services by restarting the device and putting it into maintenance mode. This issue impacts: PAN-OS 8.1 versions earlier than PAN-OS 8.1.21; PAN-OS 9.0 versions earlier than PAN-OS 9.0.14-h4; PAN-OS 9.1 versions earlier than PAN-OS 9.1.11-h3; PAN-OS 10.0 versions earlier than PAN-OS 10.0.8-h4; PAN-OS 10.1 versions earlier than PAN-OS 10.1.3. Prisma Access customers are not impacted by this issue.
- Record
EUVD-2021-26415- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-2h4v-5pj9-9hm9No score
An improper handling of exceptional conditions vulnerability exists in Palo Alto Networks...
An improper handling of exceptional conditions vulnerability exists in Palo Alto Networks GlobalProtect portal and gateway interfaces that enables an unauthenticated network-based attacker to send specifically crafted traffic to a GlobalProtect interface that causes the service to stop responding. Repeated attempts to send this request result in denial of service to all PAN-OS services by restarting the device and putting it into maintenance mode. This issue impacts: PAN-OS 8.1 versions earlier than PAN-OS 8.1.21; PAN-OS 9.0 versions earlier than PAN-OS 9.0.14-h4; PAN-OS 9.1 versions earlier than PAN-OS 9.1.11-h3; PAN-OS 10.0 versions earlier than PAN-OS 10.0.8-h4; PAN-OS 10.1 versions earlier than PAN-OS 10.1.3. Prisma Access customers are not impacted by this issue.
- Record
GHSA-2h4v-5pj9-9hm9- Weakness
- CWE-755
- Updated
- 2026-11-02
NVD
An improper handling of exceptional conditions vulnerability exists in Palo Alto Networks GlobalProtect portal and gateway interfaces that enables an unauthenticated network-based attacker to send specifically crafted traffic to a GlobalProtect interface that causes the service to stop responding. Repeated attempts to send this request result in denial of service to all PAN-OS services by restarting the device and putting it into maintenance mode. This issue impacts: PAN-OS 8.1 versions earlier than PAN-OS 8.1.21; PAN-OS 9.0 versions earlier than PAN-OS 9.0.14-h4; PAN-OS 9.1 versions earlier than PAN-OS 9.1.11-h3; PAN-OS 10.0 versions earlier than PAN-OS 10.0.8-h4; PAN-OS 10.1 versions earlier than PAN-OS 10.1.3. Prisma Access customers are not impacted by this issue.
- Record
CVE-2021-3063- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:N/I:N/A:P - Weakness
- CWE-755
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-3063 is a high vulnerability (CVSS 7.5) in Palo Alto Networks Pan-os, published November 10, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.93%, the 61st percentile. No source names a fixed version.