GlobalProtect App: Buffer Overflow Vulnerability When Connecting to Portal or Gateway

published 2021-10-13 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-26409

cvss: 8.1; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 1.4%; EPSS 1.4% chance of exploitation in 30 days, percentile 73%
public exploits: 0; none known

A stack-based buffer overflow vulnerability exists in the Palo Alto Networks GlobalProtect app that enables a man-in-the-middle attacker to disrupt system processes and potentially execute arbitrary code with SYSTEM privileges. This issue impacts: GlobalProtect app 5.1 versions earlier than GlobalProtect app 5.1.9 on Windows; GlobalProtect app 5.2 versions earlier than GlobalProtect app 5.2.8 on Windows; GlobalProtect app 5.2 versions earlier than GlobalProtect app 5.2.8 on the Universal Windows Platform; GlobalProtect app 5.3 versions earlier than GlobalProtect app 5.3.1 on Linux.

Patch / fix

fixed in 1

Palo Alto Networks GlobalProtect App 5.1.9, 5.2.8, 5.3.1

Exploit prediction

1.43% chance of exploitation in the next 30 days, higher than 73% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	8.1	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	9.3	AV:N/AC:M/Au:N/C:C/I:C/A:C

Affected products

Palo Alto Networks GlobalProtect App

Classification

Weakness

CWE-121 Stack-based Buffer Overflow
CWE-787 Out-of-bounds Write

References

security.paloaltonetworks.com /CVE-2021-3057
vendor-advisory

Sources

CVE List CVE-2021-3057
NVD CVE-2021-3057

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.

Summary