CVE-2021-3056: palo alto networks pan-os Classic Buffer Overflow
Vulnerability summary
CVE-2021-3056 is a high (CVSS 8.8) Classic Buffer Overflow vulnerability in palo alto networks pan-os. EPSS estimates a 1.54% chance of exploitation in the next 30 days, higher than 74.6% of scored vulnerabilities.
Timeline
- 10-11-2021PublishedVulnerability first disclosed.
- 16-09-2024Last modifiedVulnerability information updated.
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.
CVSS metrics
3 scores · 2 sources · 2 versions- NVDNIST8.8HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
1.54%
Chance of exploitation in the next 30 days
Percentile
75%
Versus all other CVEs
30-day change
0.00 pp
From 1.54% on 21-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.
- CWE-787Out-of-bounds WriteThe product writes data past the end, or before the beginning, of the intended buffer.
Affected systems
Palo alto networks2 products
- pan-os≥ 9.0, < 9.0.14 | ≥ 8.1, < 8.1.20 | ≥ 9.1, < 9.1.9 | ≥ 10.0, < 10.0.1
- prisma access2.1 Preferred
Paloaltonetworks1 product
- pan-osEOL≥ 8.1.0, < 8.1.20 | ≥ 9.0.0, < 9.0.14 | ≥ 9.1.0, < 9.1.9 | 10.0.0
2 vendors · 3 products