CVE record · CVE-2021-20038

Stack-based buffer overflow in SonicWall SMA100

CVSS 9.8 CriticalCriticalIn CISA KEV · ransomwareEPSS 1.00 · 99th percentile

Critical, because:

In CISA’s KEV catalogue since 28 Jan 2022: it is known to be exploited.
CVSS score 9.8: 9.0 or more.
CVSS score 9.8 (7.0 or more) and EPSS 1.00 (0.1 or more): a high score and a real chance of exploitation in the next 30 days.

Published by the CVE Program (CNA: sonicwall) at 8 Dec 2021, 09:55 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

Affected products, as the CNA wrote them
Vendor	Product	Versions
SonicWall	SonicWall SMA100	affected 10.2.0.8-37sv and earlier affected 10.2.1.1-19sv and earlier affected 10.2.1.2-24sv and earlier

Identifiers: CVE-2021-20038
CNA: sonicwall
Weakness (CWE): CWE-121
Tags: SonicWall SMA100
Memory corruption
Published: 8 Dec 2021
Updated: 21 Oct 2025

Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
9.8	Critical	3.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H	ADP (CISA-ADP)

CISA KEV Listed since 28 Jan 2022: known to be exploited. CISA reports use in ransomware campaigns.
EPSS 1.00, the 99th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

This record came from the full history of the CVE Program, published 8 Dec 2021. New records show when each source confirmed them.

Sources

References from the CNA

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.