CASCACascade Atlas

Evidence dossier

CVE-2021-36741

An improper input validation vulnerability in Trend Micro Apex One, Apex One as a Service, OfficeScan XG, and Worry-Free Business Security 10.0 SP1 allows a remote attached to…

Exploited in the wild (CISA KEV since Nov 3, 2021). NVD reports CVSS 3.1 8.8. EPSS estimates 5.0% exploit likelihood as of Aug 27, 2026.

71.1–73.6Priority evidence range
Evidence current through Aug 27, 2026, 6:09 PM UTC

As of Aug 27, 2026

Normalized restatement

An improper input validation vulnerability in Trend Micro Apex One, Apex One as a Service, OfficeScan XG, and Worry-Free Business Security 10.0 SP1 allows a remote attached to upload arbitrary files on affected installations. Please note: an attacker must first obtain the ability to logon to the product�s management console in order to exploit this vulnerability.

State
PUBLISHED
Published
Jul 29, 2021
Updated
Oct 21, 2025
Evidence coverage
93%

Evidence chronology

What was known when

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  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
    trendmicro

    Record text: An improper input validation vulnerability in Trend Micro Apex One, Apex One as a Service, OfficeScan XG, and Worry-Free Business Security 10.0 SP1 allows a remote attached to upload arbitrary files on affected installations. Please note: an attacker must first obtain the ability to logon to the product�s management console in order to exploit this vulnerability.

    Inspect raw assertion
    Field
    container
    Value
    An improper input validation vulnerability in Trend Micro Apex One, Apex One as a Service, OfficeScan XG, and Worry-Free Business Security 10.0 SP1 allows a remote attached to upload arbitrary files on affected installations. Please note: an attacker must first obtain the ability to logon to the product�s management console in order to exploit this vulnerability.
    Original evidence ↗
  4. Source dateFirst observed by CASCA
    CISA KEV

    Exploitation cataloged: Trend Micro Multiple Products Improper Input Validation Vulnerability

    Inspect raw assertion
    Field
    observed_exploitation
    Value
    Trend Micro Multiple Products Improper Input Validation Vulnerability
    Original evidence ↗
  5. Source dateFirst observed by CASCA
    FIRST EPSS

    EPSS score: 4.95% probability · 91.53th percentile

    Inspect raw assertion
    Field
    model_probability
    Value
    Probability 0.049510000000; percentile 0.915310000000
    Original evidence ↗
ExploitationCatalog member

CISA KEV · catalog date Nov 3, 2021 · first observed Jul 19, 2026

Exploit likelihood4.95%

FIRST EPSS · score date Aug 27, 2026 · 91.5th percentile · first observed Aug 27, 2026

SeverityCVSS 8.8

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 ↗
trendmicroOriginal assertion
Record text

An improper input validation vulnerability in Trend Micro Apex One, Apex One as a Service, OfficeScan XG, and Worry-Free Business Security 10.0 SP1 allows a remote attached to upload arbitrary files on affected installations. Please note: an attacker must first obtain the ability to logon to the product�s management console in order to exploit this vulnerability.

Inspect raw assertion
Field
container
Value
An improper input validation vulnerability in Trend Micro Apex One, Apex One as a Service, OfficeScan XG, and Worry-Free Business Security 10.0 SP1 allows a remote attached to upload arbitrary files on affected installations. Please note: an attacker must first obtain the ability to logon to the product�s management console in order to exploit this vulnerability.
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CISA KEVOriginal assertion
Exploitation cataloged

Trend Micro Multiple Products Improper Input Validation Vulnerability

Inspect raw assertion
Field
observed_exploitation
Value
Trend Micro Multiple Products Improper Input Validation Vulnerability
Source dateFirst observed by CASCAOriginal evidence ↗
FIRST EPSSOriginal assertion
EPSS score

4.95% probability · 91.53th percentile

Inspect raw assertion
Field
model_probability
Value
Probability 0.049510000000; percentile 0.915310000000
Source dateFirst observed by CASCAOriginal evidence ↗

Applicability

Cited product scope

Trace impact →
5Underlying assertions
5Canonical products
4Target assertions
1Constraint assertions

Grouped from 3 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

8 scope groups

trendmicro · source assertedTrend MicroTrend Micro Apex OneDirect source scope
Affected: 2019, SaaS
Source-reported scope

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

Inspect raw assertion[{"status": "affected", "version": "2019, SaaS"}]
trendmicro · source assertedTrend MicroTrend Micro OfficeScanDirect source scope
Affected: XG SP1
Source-reported scope

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

Inspect raw assertion[{"status": "affected", "version": "XG SP1"}]
trendmicro · source assertedTrend MicroTrend Micro Worry-Free Business SecurityDirect source scope
Affected: 10.0 SP1
Source-reported scope

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

Inspect raw assertion[{"status": "affected", "version": "10.0 SP1"}]
NVD CPE · OPERATING SYSTEMmicrosoftwindowsEnvironmental constraint · 1 assertions
Version not applicableCanonical identity product-6a798dc931affc038ba266631a506d54b455ffebd96b4fae68f77b6bd7aef178Linked exact
Scope constrained
Inspect raw assertion
  1. cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Environmental constraint
    Configuration
    1 · node/0 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    a2572d17-1de6-457b-99cc-64afd54487ea
NVD CPE · APPLICATIONtrendmicroapex_oneVulnerable target · 1 assertions
Version 2019Canonical identity product-c36b03ede89735893cf5eb7227d4471fd5a59b5023d788d61a15bc2c37404e58Linked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:a:trendmicro:apex_one:2019:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    1 · node/1 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    af019d2d-c426-4d2d-a254-442ce777b41e
NVD CPE · APPLICATIONtrendmicroofficescanVulnerable target · 1 assertions
Version xgCanonical identity product-ddbe4be1ec1bed754a10ed087761d8367ba7e4e7c79eeb161895dc5fdd260a4eLinked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:a:trendmicro:officescan:xg:sp1:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    64600b42-4884-41f2-a683-ae1edb79372e
NVD CPE · APPLICATIONtrendmicroofficescan_business_securityVulnerable target · 1 assertions
Version 10.0Canonical identity product-580a5f592715e8aea82907d5032e70a544e450e6bd0eb4c74643f4fda22f7ee7Linked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:a:trendmicro:officescan_business_security:10.0:sp1:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 1
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    762313f8-2ba6-4ed7-a977-56c962d5b27f
NVD CPE · APPLICATIONtrendmicroworry-free_business_securityVulnerable target · 1 assertions
Version 10.0Canonical identity product-9ed062761919e7593cb5621fedcfbc9e01b23dcc03ee3dc071be457a5a95cefaLinked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:a:trendmicro:worry-free_business_security:10.0:sp1:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    1 · node/1 · match 1
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    ffce8717-85d2-4f4f-91df-c6da341c4e19

Affected-product evidence

Accepted scope and product mapping

4 canonical links · 1 source-reported links

Mapping establishedEvidence supported

vendor-8fd269160415a9916bfdec3c59c8034a460623e87d0d40380828bdbac86a50ec · product-580a5f592715e8aea82907d5032e70a544e450e6bd0eb4c74643f4fda22f7ee7

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
4fa22e91-64e8-42c9-942d-89f063c61a17
Mapping establishedEvidence supported

vendor-8fd269160415a9916bfdec3c59c8034a460623e87d0d40380828bdbac86a50ec · product-9ed062761919e7593cb5621fedcfbc9e01b23dcc03ee3dc071be457a5a95cefa

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
e2c83dd2-cbc3-4716-b402-3dfabf6143e7
Mapping establishedEvidence supported

vendor-8fd269160415a9916bfdec3c59c8034a460623e87d0d40380828bdbac86a50ec · product-c36b03ede89735893cf5eb7227d4471fd5a59b5023d788d61a15bc2c37404e58

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
ab1a6b9d-7be1-4d32-aaf4-7e53ff5fbe52
Mapping establishedEvidence supported

vendor-8fd269160415a9916bfdec3c59c8034a460623e87d0d40380828bdbac86a50ec · product-ddbe4be1ec1bed754a10ed087761d8367ba7e4e7c79eeb161895dc5fdd260a4e

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
cd180853-1ab0-41de-9424-d48ef56ec75d
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
3
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
2a6722ec-6f3b-428a-bfcc-afd0ebcb40bede8f2f2f-0bb7-49c7-97a3-a055311e3a68fe1ebcbf-69e5-4996-b7bf-bfe77efc7f3d

Assessments

CVSS by origin

8.8
NVDCVSS 3.1 · role Primary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
6.5
NVDCVSS 2.0 · role Primary · priority eligiblevalid_matchAV:N/AC:L/Au:S/C:P/I:P/A:P
8.8
CVE Program sourceCVSS 3.1 · role Secondary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
8.8
CISA-ADPCVSS 3.1 · role unknown · display onlyDirect record assessment retained outside normalized eligibilityCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Direct CVE/CNA normalized decisions

8.8Priority eligible

CISA-ADP

CVSS 3.1 · Secondary · Independent enrichment · rank 2

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Validation
Valid match
Recomputed
8.8
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.