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Fencer Vulns
high 7.5

CVE-2021-3063 json

PAN-OS: Denial-of-Service (DoS) Vulnerability in GlobalProtect Portal and Gateway Interfaces

published 2021-11-10 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-26415

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 60%
public exploits
0
none known

Summary

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.

Patch / fix

  • Palo Alto Networks PAN-OS 8.1.21, 9.0.14-h4, 9.1.11-h3, 10.0.8-h4, 10.1.3

Exploit prediction

0.93% chance of exploitation in the next 30 days, higher than 60% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:N/I:N/A:P

Affected products

  • Palo Alto Networks PAN-OS
  • Palo Alto Networks Prisma Access

Classification

Weakness
  • CWE-755 Improper Handling of Exceptional Conditions
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.