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ExploitedIn CISA KEV

CVE-2021-20038

Exploitation confirmed. First attested on 2022-01-28 by CISA-ADP, CISA KEV, GCVE · kevintel.

  • Published2021-12-08
  • WeaknessCWE-121 · CWE-787

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

A Stack-based buffer overflow vulnerability in SMA100 Apache httpd server's mod_cgi module environment variables allows a remote unauthenticated attacker to potentially execute code as a 'nobody' user in the appliance. This vulnerability affected SMA 200, 210, 400, 410 and 500v appliances firmware 10.2.0.8-37sv, 10.2.1.1-19sv, 10.2.1.2-24sv and earlier versions.

Timeline

dates in UTC
  1. 2021-12-0810:15CVE publishedNVD
  2. 2022-01-28Added to the CISA KEV catalogCISA KEV
  3. 2022-01-28Listed as exploited by GCVEGCVE
  4. 2022-01-28Exploitation first reportedCISA KEV
  5. 2025-02-0414:26SSVC exploitation set to activeCISA-ADP

Observed activity

isMalicious corpus · updated 2026-11-03 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-20038?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-20038?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Sonicwall sma 200 firmwareversion to verify
BranchAffectedFixed in
10.2= 10.2.0.8-37svno fix published
10.2= 10.2.1.1-19svno fix published
10.2= 10.2.1.2-24svno fix published
Sonicwall sma 210 firmwareversion to verify
BranchAffectedFixed in
10.2= 10.2.0.8-37svno fix published
10.2= 10.2.1.1-19svno fix published
10.2= 10.2.1.2-24svno fix published
Sonicwall sma 400 firmwareversion to verify
BranchAffectedFixed in
10.2= 10.2.0.8-37svno fix published
10.2= 10.2.1.1-19svno fix published
10.2= 10.2.1.2-24svno fix published

2 more products in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Products declared by the CNA1 product

As sonicwall, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

  • SonicWall SMA100
    Affected
    • = 10.2.0.8-37sv and earlierno fix stated
    • = 10.2.1.1-19sv and earlierno fix stated
    • = 10.2.1.2-24sv and earlierno fix stated

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2022-04-29

Fix

  1. CISA’s required action: Apply updates per vendor instructions.due 2022-02-11

Advisories and patches

Detection

read 2026-11-02 22:42 UTC
Nuclei template
available
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
3 repositories, unverifiedjbaines-r7/badbloodvesperp/CVE-2021-20038-SonicWall-RCEanir0y/sonicwall-audit-toolkit
PoC-in-GitHub
Metasploit modules
none listed
Metasploit Framework

CISA Known Exploited Vulnerability

Date Added
2022-01-28
Patch Due Date
2022-02-11
Ransomware Use
Known
Required Action
Apply updates per vendor instructions.

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published
2021-12-08
Last Modified
2026-06-17
NVD status
Analyzed
GitHub Advisory
GHSA-jmhc-vxg9-h2g4

Frequently asked questions

What is CVE-2021-20038?

A Stack-based buffer overflow vulnerability in SMA100 Apache httpd server's mod_cgi module environment variables allows a remote unauthenticated attacker to potentially execute code as a 'nobody' user in the appliance. This vulnerability affected SMA 200, 210, 400, 410 and 500v appliances firmware 10.2.0.8-37sv, 10.2.1.1-19sv, 10.2.1.2-24sv and earlier versions.

Is CVE-2021-20038 actively exploited?

Yes. CVE-2021-20038 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 2022-02-11.

What is the CVSS score for CVE-2021-20038?

CVE-2021-20038 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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Sources for this record