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ExploitedIn CISA KEVFix available

CVE-2021-20035

Exploitation confirmed. First attested on 2025-04-16 by CISA-ADP, CISA KEV, GCVE · kevintel.

  • Published2021-09-27
  • Fixed in10.2.1.1-19sv · 10.2.0.8-37sv · 9.0.0.11-31sv
  • WeaknessCWE-78

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

Improper neutralization of special elements in the SMA100 management interface allows a remote authenticated attacker to inject arbitrary commands as a 'nobody' user which potentially leads to DoS.

Timeline

dates in UTC
  1. 2021-09-2718:15CVE publishedNVD
  2. 2025-04-16Added to the CISA KEV catalogCISA KEV
  3. 2025-04-16Listed as exploited by GCVEGCVE
  4. 2025-04-16Exploitation first reportedCISA KEV
  5. 2025-04-1703:55SSVC 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-2021-20035?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-20035?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≥ 10.2.1.0, < 10.2.1.1-19sv10.2.1.1-19sv
10.2≥ 10.2.0.0, < 10.2.0.8-37sv10.2.0.8-37sv
9.0< 9.0.0.11-31sv9.0.0.11-31sv
Sonicwall sma 210 firmwareversion to verify
BranchAffectedFixed in
10.2≥ 10.2.1.0, < 10.2.1.1-19sv10.2.1.1-19sv
10.2≥ 10.2.0.0, < 10.2.0.8-37sv10.2.0.8-37sv
9.0< 9.0.0.11-31sv9.0.0.11-31sv
Sonicwall sma 400 firmwareversion to verify
BranchAffectedFixed in
10.2≥ 10.2.1.0, < 10.2.1.1-19sv10.2.1.1-19sv
10.2≥ 10.2.0.0, < 10.2.0.8-37sv10.2.0.8-37sv
9.0< 9.0.0.11-31sv9.0.0.11-31sv

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
    • = 9.0.0.10-28sv and earlierno fix stated
    • = 10.2.0.7-34sv and earlierno fix stated
    • = 10.2.1.0-17sv and earlierno fix stated

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2021-09-27

Fix

  1. Update Sonicwall sma 200 firmware to 10.2.1.1-19sv · 10.2.0.8-37sv · 9.0.0.11-31sv
  2. CISA’s required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.due 2025-05-07

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub
Metasploit modules
none listed
Metasploit Framework

CISA Known Exploited Vulnerability

Date Added
2025-04-16
Patch Due Date
2025-05-07
Ransomware Use
Unknown
Required Action
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Published
2021-09-27
Last Modified
2026-06-17
NVD status
Analyzed
GitHub Advisory
GHSA-g24w-7v2m-52xh

Frequently asked questions

What is CVE-2021-20035?

Improper neutralization of special elements in the SMA100 management interface allows a remote authenticated attacker to inject arbitrary commands as a 'nobody' user which potentially leads to DoS.

Is CVE-2021-20035 actively exploited?

Yes. CVE-2021-20035 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 2025-05-07.

What is the CVSS score for CVE-2021-20035?

CVE-2021-20035 has a CVSS v3 base score of 6.5 (MEDIUM severity), with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

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Sources for this record