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NVD / CVE Program· CNA sonicwall

CVE-2021-20038: A Stack-based buffer overflow vulnerability in SMA100 Apache httpd server's mod_cgi module environment variables allows a remote…

CriticalCVSS 9.8 · v3.1KEVWeaponized No fix recorded

Noroxi assessment

Priority: Now (action score 99/100)

  • CISA has confirmed exploitation in the wild (Jan 28, 2022); it is known to be used in ransomware campaigns. Remediation deadline for US federal agencies: Feb 11, 2022.
  • A ready-made attack module is public (Nuclei); exploiting it takes no special expertise.
  • Probability of exploitation in the next 30 days: 99.9% (FIRST EPSS); higher than 99.9% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • According to the record, no fixed version is available yet.
  • Mentioned 3 times in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Patch today or shut off access. Until a fix is released, restrict access to the affected component and follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · CISA KEV · FIRST EPSS

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.

Published
Dec 8, 2021
Updated
Jun 16, 2026
EPSS
99.9% · 99th percentile

Report tools

JSON

Action score

99

Now

Patch today or shut off access.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
30 / 30 · Listed
EPSS
30 / 30 · 99.9%

CISA SSVC decision

Exploitation
active
Automatable
yes
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

Actively exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on Jan 28, 2022. That signals real attacks, not theory.

Remediation deadline for US federal agencies: Feb 11, 2022.

Known to be used in ransomware campaigns.

Get told when this record changes

  • In CISA KEV: exploitation in the wild confirmed
  • Weaponized exploit exists
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2021-20038

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits every 10 minutes on paid plans, on the hour on the free plan.

Your free account also gets you

  • CVE alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools, at most 30 a day (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
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Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
sonicwallsma 200 firmware
sonicwallsma 200
sonicwallsma 210 firmware
sonicwallsma 210
sonicwallsma 410 firmware
sonicwallsma 410
sonicwallsma 400 firmware
sonicwallsma 400
sonicwallsma 500v firmware
sonicwallsma 500v

Using sma 200 firmware? Add it to your stack and be the first to know about CVEs like this one. (VPN gateway)

Watch new CVEs for sma 200 firmware

When you'll hear from us

  • when a new CVE affecting this product is published
  • when a record in your stack enters KEV or is weaponized

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits every 10 minutes on paid plans, on the hour on the free plan.

Your free account also gets you

  • CVE alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools, at most 30 a day (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every Monday

Versions reported by the vendor

Affected version ranges reported by the assigning authority (sonicwall). Independent of NVD's CPE analysis and usually ahead of it.

  • SonicWall SonicWall SMA100

    • 10.2.0.8-37sv and earlier, 10.2.1.1-19sv and earlier, 10.2.1.2-24sv and earlieraffected
Affected versions · NVD (15)

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • sonicwall sma 200 firmware10.2.0.8-37sv
  • sonicwall sma 200 firmware10.2.1.1-19sv
  • sonicwall sma 200 firmware10.2.1.2-24sv
  • sonicwall sma 210 firmware10.2.0.8-37sv
  • sonicwall sma 210 firmware10.2.1.1-19sv
  • sonicwall sma 210 firmware10.2.1.2-24sv
  • sonicwall sma 400 firmware10.2.0.8-37sv
  • sonicwall sma 400 firmware10.2.1.1-19sv
  • sonicwall sma 400 firmware10.2.1.2-24sv
  • sonicwall sma 410 firmware10.2.0.8-37sv
  • sonicwall sma 410 firmware10.2.1.1-19sv
  • sonicwall sma 410 firmware10.2.1.2-24sv
  • sonicwall sma 500v firmware10.2.0.8-37sv
  • sonicwall sma 500v firmware10.2.1.1-19sv
  • sonicwall sma 500v firmware10.2.1.2-24sv

Same product

sonicwall: all records

Other highest-scoring records for the same primary product.

  • CVE-2023-44221Improper neutralization of special elements in the SMA100 SSL-VPN management interface allows a remote authenticated attacker with…KEV
    81Now
  • CVE-2021-20034An improper access control vulnerability in SMA100 allows a remote unauthenticated attacker to bypass the path traversal checks and delete…
    61This week
  • CVE-2021-20039Improper neutralization of special elements in the SMA100 management interface '/cgi-bin/viewcert' POST http method allows a remote…
    59Plan

Published before and after this one in the same product

  • ← EarlierCVE-2021-20035Sep 27, 2021 · Improper neutralization of special elements in the SMA100 management interface allows a remote authenticated attacker to inject arbitrary…KEV
    57Plan
  • Later →CVE-2021-20040Dec 8, 2021 · A relative path traversal vulnerability in the SMA100 upload funtion allows a remote unauthenticated attacker to upload crafted web pages…
    38Monitor
  • Later →CVE-2021-20041Dec 8, 2021 · An unauthenticated and remote adversary can consume all of the device's CPU due to crafted HTTP requests sent to SMA100…
    36Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

Weaponized

A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.

Evidence

  • Nuclei detection template ×1
  • Proof-of-concept repository on GitHub ×3

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHub3 repositories2022-01-11 → 2026-02-23
Nuclei detection templateNuclei template CVE-2021-20038 —

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. First PoC+34 d
  3. CISA KEV+51 d
  4. TodayNov 14, 2026+1802 d

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-121 · Stack-based Buffer Overflow

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records