CVE-2021-20038VulnerabilityPublished 01/28/2022Updated 10/24/2026

CVE-2021-20038: SonicWall SMA 100 Appliances Stack-Based Buffer Overflow Vulnerability

Affects SonicWall SMA 100 AppliancesSource CISA KEV

Severity

High

No CVSS score published yet

Exploitation: Actively exploited – in CISA KEV since 01/28/2022
KEV deadline: 02/11/2022
Ransomware: Used in ransomware campaigns
EPSS: 99.9% chance of exploitation in 30 days – higher than 99% of CVEs

What to do

CISA required action

Apply updates per vendor instructions.

nvd.nist.gov/vuln/detail/CVE-2021-20038 (opens in a new tab)

Description

SonicWall SMA 100 Appliances are affected by an unauthenticated stack-based buffer overflow vulnerability (CVE-2021-20038) that can lead to remote code execution. This vulnerability has been exploited in the wild and is known to be used in ransomware campaigns. No specific affected versions or patch information is provided in the available data.

Summary

CVE-2021-20038 describes a stack-based buffer overflow vulnerability in SonicWall SMA 100 Appliances. The flaw allows unauthenticated attackers to trigger a buffer overflow condition, potentially enabling arbitrary code execution on the affected device. This vulnerability has been observed in active exploitation scenarios, including ransomware attacks.

Impact

Successful exploitation of this vulnerability can result in remote code execution without authentication, allowing attackers to take control of the affected SonicWall SMA 100 Appliance. This can lead to compromise of network security and facilitate ransomware deployment.

Mitigation

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a patch is available, monitor vendor communications for updates and consider applying any recommended temporary mitigations.

Weaknesses

CWE-121Stack-based Buffer Overflow (opens in a new tab)

What to do

Description

AnalysisAI-generated, updated 10/24/2026, 10:10:46 UTC

Weaknesses

References

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