CASCACascade Atlas

Evidence dossier

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…

Exploited in the wild (CISA KEV since Jan 28, 2022). NVD reports CVSS 3.1 9.8. EPSS estimates 99.9% exploit likelihood as of Aug 8, 2026.

89.5–90.5Priority evidence range
Evidence current through Aug 27, 2026, 6:09 PM UTC

As of Aug 27, 2026

Normalized restatement

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.

State
PUBLISHED
Published
Dec 8, 2021
Updated
Oct 21, 2025
Evidence coverage
99%

Evidence chronology

What was known when

Download this view's receipt →
  1. Source dateSource date omittedFirst observed by CASCA
    CISA-ADP

    Record text: CISA ADP Vulnrichment

    Inspect raw assertion
    Field
    container
    Value
    CISA ADP Vulnrichment
    Original evidence ↗
  2. Source dateSource date omittedFirst observed by CASCA
    CVE Program

    Record text: CVE Program Container

    Inspect raw assertion
    Field
    container
    Value
    CVE Program Container
    Original evidence ↗
  3. Source dateSource date omittedFirst observed by CASCA
    sonicwall

    Record text: 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.

    Inspect raw assertion
    Field
    container
    Value
    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.
    Original evidence ↗
  4. Source dateFirst observed by CASCA
    CISA KEV

    Exploitation cataloged: SonicWall SMA 100 Appliances Stack-Based Buffer Overflow Vulnerability

    Inspect raw assertion
    Field
    observed_exploitation
    Value
    SonicWall SMA 100 Appliances Stack-Based Buffer Overflow Vulnerability
    Original evidence ↗
  5. Source dateFirst observed by CASCA
    FIRST EPSS

    EPSS score: 99.9% probability · 99.97th percentile

    Inspect raw assertion
    Field
    model_probability
    Value
    Probability 0.998990000000; percentile 0.999650000000
    Original evidence ↗
ExploitationCatalog member

CISA KEV · catalog date Jan 28, 2022 · first observed Jul 19, 2026

Exploit likelihood99.90%

FIRST EPSS · score date Aug 8, 2026 · 100th percentile · first observed Aug 8, 2026

SeverityCVSS 9.8

NVD · CVSS 3.1 · first observed Jul 19, 2026 · same-version scores align in this snapshot

Evidence detail

Source limits and decisions

Why each evidence state has this value

casca-unknown-reasons-v1
Exploitation statusEvidence supported

Eligible evidence is present for this bounded claim.

Revision
evidence-policy-v1.1.0
Cutoff
Aug 27, 2026
Resolution
None
Exploit likelihoodEvidence supported

Eligible evidence is present for this bounded claim.

Revision
evidence-policy-v1.1.0
Cutoff
Aug 27, 2026
Resolution
None
Severity assessmentEvidence supported

Eligible evidence is present for this bounded claim.

Revision
casca-direct-cvss-eligibility-v1
Cutoff
Aug 27, 2026
Resolution
None
Affected productsSource-reported scope

The cited source assertion is retained while canonical product linkage remains open.

Revision
casca-factor-d-obligations-v1
Cutoff
Aug 27, 2026
Resolution
Resolve identity

Source comparison

Who said what

CISA-ADPIndependent enrichment
Record text

CISA ADP Vulnrichment

Inspect raw assertion
Field
container
Value
CISA ADP Vulnrichment
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CVE ProgramDerivative copy
Record text

CVE Program Container

Inspect raw assertion
Field
container
Value
CVE Program Container
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
sonicwallOriginal assertion
Record text

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.

Inspect raw assertion
Field
container
Value
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.
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CISA KEVOriginal assertion
Exploitation cataloged

SonicWall SMA 100 Appliances Stack-Based Buffer Overflow Vulnerability

Inspect raw assertion
Field
observed_exploitation
Value
SonicWall SMA 100 Appliances Stack-Based Buffer Overflow Vulnerability
Source dateFirst observed by CASCAOriginal evidence ↗
FIRST EPSSOriginal assertion
EPSS score

99.9% probability · 99.97th percentile

Inspect raw assertion
Field
model_probability
Value
Probability 0.998990000000; percentile 0.999650000000
Source dateFirst observed by CASCAOriginal evidence ↗

Applicability

Cited product scope

Trace impact →
20Underlying assertions
10Canonical products
15Target assertions
5Constraint assertions

Grouped from 10 configuration nodes in this exact snapshot. Visual grouping is navigational; asset exposure and root cause require cited evidence.

Identity source boundaries
  • Cpe dictionary1,775,266 records · observed through 2026-07-21T06:45:29.809Z27d65b0f-b718-4b4f-bb79-c47c68d09dfa
  • Cpe match643,502 records · observed through 2026-07-21T08:13:17.697Z955dae73-7302-438b-aee1-058d7cc5d48e

11 scope groups

sonicwall · source assertedSonicWallSonicWall SMA100Direct source scope
Affected: 10.2.0.8-37sv and earlierAffected: 10.2.1.1-19sv and earlierAffected: 10.2.1.2-24sv and earlier
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "10.2.0.8-37sv and earlier"}, {"status": "affected", "version": "10.2.1.1-19sv and earlier"}, {"status": "affected", "version": "10.2.1.2-24sv and earlier"}]
NVD CPE · HARDWAREsonicwallsma_200Environmental constraint · 1 assertions
Version not applicableCanonical identity product-91e31bab8ca12568b55fbef81208d65415eb9ae4c788d26be09141b79c89fe9dLinked exact
Scope constrained
Inspect raw assertion
  1. cpe:2.3:h:sonicwall:sma_200:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Environmental constraint
    Configuration
    0 · node/1 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    0b190266-ad6f-401b-9b2e-061cdd539236
NVD CPE · OPERATING SYSTEMsonicwallsma_200_firmwareVulnerable target · 3 assertions
Version 10.2.0.8-37sv; Version 10.2.1.1-19sv; Version 10.2.1.2-24svCanonical identity product-1a893bd70f781870bc12b4b23d779710e6905e394bbc481fb889b05ce4182e74Linked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:o:sonicwall:sma_200_firmware:10.2.1.1-19sv:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 1
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    33233a45-6667-4ce9-a21c-6a6c725689f8
  2. cpe:2.3:o:sonicwall:sma_200_firmware:10.2.0.8-37sv:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    4185c028-6a07-4a92-8380-9aa3953d2cfd
  3. cpe:2.3:o:sonicwall:sma_200_firmware:10.2.1.2-24sv:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 2
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    01134e66-f1fd-477b-ad44-fdee8368be18
NVD CPE · HARDWAREsonicwallsma_210Environmental constraint · 1 assertions
Version not applicableCanonical identity product-550c36468c01a04863339c98e9cf24a57015da41e26d7cfe3817f5627349f033Linked exact
Scope constrained
Inspect raw assertion
  1. cpe:2.3:h:sonicwall:sma_210:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Environmental constraint
    Configuration
    1 · node/1 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    51587338-4a5f-41fc-9497-743f061947c2
NVD CPE · OPERATING SYSTEMsonicwallsma_210_firmwareVulnerable target · 3 assertions
Version 10.2.0.8-37sv; Version 10.2.1.1-19sv; Version 10.2.1.2-24svCanonical identity product-26a307663a0d7d21d37685d5626bda794a31e21aa834b2d2545700514a0e4c1bLinked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:o:sonicwall:sma_210_firmware:10.2.1.2-24sv:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    1 · node/0 · match 2
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    b38aab98-7668-4f34-8d5f-9933422f12dd
  2. cpe:2.3:o:sonicwall:sma_210_firmware:10.2.1.1-19sv:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    1 · node/0 · match 1
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    e4f1c135-a182-4233-b7fc-d08c754ece13
  3. cpe:2.3:o:sonicwall:sma_210_firmware:10.2.0.8-37sv:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    1 · node/0 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    e62eec93-6f52-4ddb-95f0-d5736391d64c
NVD CPE · HARDWAREsonicwallsma_400Environmental constraint · 1 assertions
Version not applicableCanonical identity product-281c97c08cce404bae4214669fa0d9b53f5e61e0badba682846d190c941a89dfLinked exact
Scope constrained
Inspect raw assertion
  1. cpe:2.3:h:sonicwall:sma_400:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Environmental constraint
    Configuration
    3 · node/1 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    9d728332-10c9-4508-b720-569d44e99543
NVD CPE · OPERATING SYSTEMsonicwallsma_400_firmwareVulnerable target · 3 assertions
Version 10.2.0.8-37sv; Version 10.2.1.1-19sv; Version 10.2.1.2-24svCanonical identity product-e8581ca167a037abd2310f553d0f4f5493779f3b17ce222e83b9e7f474047868Linked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:o:sonicwall:sma_400_firmware:10.2.0.8-37sv:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    3 · node/0 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    9be21589-3bec-4245-9939-cf50de70b12a
  2. cpe:2.3:o:sonicwall:sma_400_firmware:10.2.1.1-19sv:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    3 · node/0 · match 1
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    beb82f42-a5df-42cc-86f9-b06b39bbc202
  3. cpe:2.3:o:sonicwall:sma_400_firmware:10.2.1.2-24sv:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    3 · node/0 · match 2
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    54946a90-09ac-4387-bacb-883ae70fd5a7
NVD CPE · HARDWAREsonicwallsma_410Environmental constraint · 1 assertions
Version not applicableCanonical identity product-7fe9cf3dc83085f07a35eb26b64c02c3a3315073c07277a9510b70c9dd839ef5Linked exact
Scope constrained
Inspect raw assertion
  1. cpe:2.3:h:sonicwall:sma_410:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Environmental constraint
    Configuration
    2 · node/1 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    9dfb8fbc-ffa4-4526-b306-d5692a43dc9e
NVD CPE · OPERATING SYSTEMsonicwallsma_410_firmwareVulnerable target · 3 assertions
Version 10.2.0.8-37sv; Version 10.2.1.1-19sv; Version 10.2.1.2-24svCanonical identity product-a7f75ceec8c377c339cb86a182bbed18843ccfe642ca6bfccc536cc48e24fa59Linked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:o:sonicwall:sma_410_firmware:10.2.1.1-19sv:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    2 · node/0 · match 1
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    8ec74d70-c04b-481f-a706-6c86751996fb
  2. cpe:2.3:o:sonicwall:sma_410_firmware:10.2.1.2-24sv:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    2 · node/0 · match 2
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    9f1fa3d8-c44a-4f33-b35d-aadf8c4e45df
  3. cpe:2.3:o:sonicwall:sma_410_firmware:10.2.0.8-37sv:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    2 · node/0 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    53698bd3-43b6-4ec4-8847-e6ed9a3cb6f6
NVD CPE · HARDWAREsonicwallsma_500vEnvironmental constraint · 1 assertions
Version not applicableCanonical identity product-118b2d48e96ca7146730edba999d21029b9135d54c3f43c7114f1e7e733f30d6Linked exact
Scope constrained
Inspect raw assertion
  1. cpe:2.3:h:sonicwall:sma_500v:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Environmental constraint
    Configuration
    4 · node/1 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    a6ad8a33-7ce4-4c66-9e23-f0c9c9638770
NVD CPE · OPERATING SYSTEMsonicwallsma_500v_firmwareVulnerable target · 3 assertions
Version 10.2.0.8-37sv; Version 10.2.1.1-19sv; Version 10.2.1.2-24svCanonical identity product-4d24eaf429e3956c478e6de21d2b4e05c1b566ac61b74443712441bbe07ce6adLinked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:o:sonicwall:sma_500v_firmware:10.2.1.1-19sv:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    4 · node/0 · match 1
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    ac429f62-366b-4b68-b378-fb741f9f7fef
  2. cpe:2.3:o:sonicwall:sma_500v_firmware:10.2.0.8-37sv:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    4 · node/0 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    379f7ca2-8914-4710-ae6b-d2833605d4b8
  3. cpe:2.3:o:sonicwall:sma_500v_firmware:10.2.1.2-24sv:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    4 · node/0 · match 2
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    9395563d-9071-4ce2-baea-d6854f4ad961

Affected-product evidence

Accepted scope and product mapping

5 canonical links · 1 source-reported links

Mapping establishedEvidence supported

vendor-88ea7b4aa6d07152b297937bc7e73efc70d62904e8122e245a64c5b028d9fab0 · product-1a893bd70f781870bc12b4b23d779710e6905e394bbc481fb889b05ce4182e74

Source class
Nvd cpe vulnerable target
Assertions
3
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
031cae2d-cee3-4085-a5c9-505aa80c44e919ac6004-bbfb-4638-ae2d-24ffc2081634c4606914-1705-40df-9960-f331543998d0
Mapping establishedEvidence supported

vendor-88ea7b4aa6d07152b297937bc7e73efc70d62904e8122e245a64c5b028d9fab0 · product-26a307663a0d7d21d37685d5626bda794a31e21aa834b2d2545700514a0e4c1b

Source class
Nvd cpe vulnerable target
Assertions
3
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
97dc9fc1-26e1-4059-92d1-18b329487d239fc21659-721b-4b82-a8bb-4f9e2b73a08caf1ca8c8-3322-42e1-9768-95cea17324b6
Mapping establishedEvidence supported

vendor-88ea7b4aa6d07152b297937bc7e73efc70d62904e8122e245a64c5b028d9fab0 · product-4d24eaf429e3956c478e6de21d2b4e05c1b566ac61b74443712441bbe07ce6ad

Source class
Nvd cpe vulnerable target
Assertions
3
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
1186935a-7851-49df-a722-33e3144ed7bd5bb39c79-e2ee-453f-b4bc-26864c6b8bd8ffb6afad-d176-4f36-80ba-36719472f8df
Mapping establishedEvidence supported

vendor-88ea7b4aa6d07152b297937bc7e73efc70d62904e8122e245a64c5b028d9fab0 · product-a7f75ceec8c377c339cb86a182bbed18843ccfe642ca6bfccc536cc48e24fa59

Source class
Nvd cpe vulnerable target
Assertions
3
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
4c9ed07a-642b-4054-b88b-f05190771add687ddce3-f568-4dec-bd5c-950d4d078b966b5349f1-46f9-4d60-b98c-af304e072521
Mapping establishedEvidence supported

vendor-88ea7b4aa6d07152b297937bc7e73efc70d62904e8122e245a64c5b028d9fab0 · product-e8581ca167a037abd2310f553d0f4f5493779f3b17ce222e83b9e7f474047868

Source class
Nvd cpe vulnerable target
Assertions
3
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
074a3e50-5ac3-4f33-a75d-70b197074c48d636df01-99f8-41e5-a3a1-bd6e180b4074e6073db1-de71-4a60-9168-e655ddd1c3ec
Source-reported scopeSource-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Vendor specified only by source · Product specified only by source

Source class
Direct cve affected
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
ab722841-720e-46b9-bdc0-539d8065845b

Assessments

CVSS by origin

9.8
NVDCVSS 3.1 · role Primary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5
NVDCVSS 2.0 · role Primary · priority eligiblevalid_matchAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8
CVE Program sourceCVSS 3.1 · role Secondary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8
CISA-ADPCVSS 3.1 · role unknown · display onlyDirect record assessment retained outside normalized eligibilityCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Direct CVE/CNA normalized decisions

9.8Priority eligible

CISA-ADP

CVSS 3.1 · Secondary · Independent enrichment · rank 2

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Validation
Valid match
Recomputed
9.8
Decision reason
Evidence supported
Policy
casca-direct-cvss-eligibility-v1

Assessments are retained side by side under closed precedence. Cascade never averages CVSS.

Evidence boundaries

  • KEV membership is authoritative for the catalog, not proof of exposure in any environment.
  • EPSS is a dated model probability and not an individual-environment prediction.
  • Affected or fixed status applies only to the exact cited product and version scope; remaining scope stays source-scoped.
  • NVD-carried upstream facts remain derivative; independent corroboration requires a separately authored source.
  • Only NVD metrics validated under the generation-bound calculator are Public Priority eligible; direct CVE record metrics remain display-only.
  • NVD CVSS source eligibility is closed: NVD-authored, exact record-source, or registered same-CVE container origin; unmapped sources remain display-only.
  • Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.
  • OSV aggregation and OSV-converted NVD material are not independent corroboration.
  • Red Hat facts are vendor assertions for the exact supplied products.
  • Nonmembership and not-yet-observed states are not proof of safety.