SonicWall SMA 100 Appliances Stack-Based Buffer Overflow Vulnerability
SonicWall SMA 100 devies are vulnerable to an unauthenticated stack-based buffer overflow vulnerability where exploitation can result in code execution.
- Vendor
- SonicWall
- Product
- SMA 100 Appliances
- CVSS
- 9.8
- EPSS (exploit probability)
- 99.9%
- Status
- kevransomware use
- CISA patch-by (BOD 22-01)
- Added to KEV
Is CVE-2021-20038 being exploited?
Yes. CISA added CVE-2021-20038 to its Known Exploited Vulnerabilities catalog on . CISA only lists a CVE when it has reliable evidence of exploitation in the wild. CISA marks it as known to be used in ransomware campaigns.
FIRST's EPSS model puts the probability of exploitation activity in the next 30 days at 99.9% (scored October 14, 2026).
- CISA KEV[ LISTED ]
- ENISA EUVD (exploited)[ — ]
- CIRCL KEV[ — ]
Catalog snapshot 2026-10-21. Full cross-catalog view: /kev-comparison
What to do
CISA required actionApply updates per vendor instructions.
US federal civilian agencies must remediate by (14 days after listing) under BOD 22-01. Everyone else: that deadline is a sensible upper bound, not a target. Vendor guidance and the NVD record are linked under Source above.
Other SonicWall SMA100 Appliances CVEs we track
| CVE / Vulnerability | Severity | CVSS | EPSS | Added to KEV |
|---|---|---|---|---|
| CVE-2023-44221 SonicWall SMA100 Appliances OS Command Injection Vulnerability | [ HIGH ] | 7.2 | 76.3% | |
| CVE-2021-20035 SonicWall SMA100 Appliances OS Command Injection Vulnerability | [ MEDIUM ] | 6.5 | 4.2% | |
| CVE-2019-7483 SonicWall SMA100 Directory Traversal Vulnerability | [ HIGH ] | 7.5 | 4.0% | |
| CVE-2021-20016 SonicWall SSLVPN SMA100 SQL Injection Vulnerabilityransomware use | [ CRITICAL ] | 9.8 | 40.0% | |
| CVE-2019-7481 SonicWall SMA100 SQL Injection Vulnerabilityransomware use | [ HIGH ] | 7.5 | 99.9% |