CASCACascade Atlas

Evidence dossier

CVE-2021-27852

CVE-2021-27852

70.1–90.8Priority evidence range
As known Jul 19, 2026, 5:00 AM UTCgen-56ccdaf9

Normalized restatement

Deserialization of Untrusted Data vulnerability in CheckboxWeb.dll of Checkbox Survey allows an unauthenticated remote attacker to execute arbitrary code. This issue affects: Checkbox Survey versions prior to 7.

State
PUBLISHED
Published
May 27, 2021
Updated
Oct 21, 2025
Evidence coverage
72%
CISA KEVCatalog member

Versions 6 and earlier for this product are end-of-life and must be removed from agency networks. Versions 7 and later are not considered vulnerable.

FIRST EPSS31.95%

2026-07-18 · v2026.06.15 · percentile 98.1%

Source stateConflict visible

Distinct CVSS assessments remain side by side; none are averaged.

Source comparison

Who said what

certccoriginal assertion
container

Deserialization of Untrusted Data vulnerability in CheckboxWeb.dll of Checkbox Survey allows an unauthenticated remote attacker to execute arbitrary code. This issue affects: Checkbox Survey versions prior to 7.

CISA-ADPindependent enrichment
container

CISA ADP Vulnrichment

CVEderivative copy
container

CVE Program Container

CISA KEVoriginal assertion
observed_exploitation

Checkbox Survey Deserialization of Untrusted Data Vulnerability

FIRST EPSSoriginal assertion
model_probability

Probability 0.319460000000; percentile 0.981150000000

Applicability

Cited product scope

Trace impact →
CheckboxSurvey
[{"status": "affected", "version": "unspecified", "lessThan": "7", "versionType": "custom"}]unknown
Unknown vendorUnknown product
cpe:2.3:a:checkbox:survey:*:*:*:*:*:*:*:*; end excluding 7.0supported

Assessments

CVSS by origin

9.8
nvd@nist.govCVSS 3.1 · role PrimaryCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5
nvd@nist.govCVSS 2.0 · role PrimaryAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8
cret@cert.orgCVSS 3.1 · role SecondaryCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8
certccCVSS 3.1 · role unknownCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Limitations and unknowns

  • 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; unresolved scope remains unknown.
  • NVD-carried upstream facts remain derivative and are not independent corroboration.
  • 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.
  • Factor D is unknown in Public Core because no accepted canonical mapping-obligation ledger is present.
  • Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.