CVE-2021-3056: PAN-OS: Memory Corruption Vulnerability in GlobalProtect Clientless VPN During SAML Authentication

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-11-10 · updated 2026-06-17
Weakness: CWE-120

Description

A memory corruption vulnerability in Palo Alto Networks PAN-OS GlobalProtect Clientless VPN enables an authenticated attacker to execute arbitrary code with root user privileges during SAML authentication. This issue impacts: PAN-OS 8.1 versions earlier than PAN-OS 8.1.20; PAN-OS 9.0 versions earlier than PAN-OS 9.0.14; PAN-OS 9.1 versions earlier than PAN-OS 9.1.9; PAN-OS 10.0 versions earlier than PAN-OS 10.0.1. Prisma Access customers with Prisma Access 2.1 Preferred firewalls are impacted by this issue.

Affected products

Palo Alto Networks PAN-OS: from 8.1.0 before 8.1.20; from 9.0.0 before 9.0.14; from 9.1.0 before 9.1.9; 10.0.0 (and their updates) — fixed in 8.1.20, 9.0.14, 9.1.9
Palo Alto Networks PAN-OS: from 9.0 before 9.0.14; from 8.1 before 8.1.20; from 9.1 before 9.1.9; from 10.0 before 10.0.1 — fixed in 9.0.14, 8.1.20, 9.1.9, 10.0.1
Palo Alto Networks Prisma Access: 2.1 Preferred

How to fix

Upgrade to a fixed version: Palo Alto Networks PAN-OS 8.1.20, 9.0.14, 9.1.9; Palo Alto Networks PAN-OS 9.0.14, 8.1.20, 9.1.9, 10.0.1. Check the vendor advisory for mitigations.

References

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