CVE-2021-43177

lowpriority · track · 21EPSS 0.009 · 59 %ileEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.88% (59th) EPSS

CVSS 3.5 · low

Is it mine?

3 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · nvd · osv

EPSS · scored 2026-10-28

As a result of an incomplete fix for CVE-2015-7225, in versions of devise-two-factor prior to 4.0.2 it is possible to reuse a One-Time-Password (OTP) for one (and only one) immediately trailing interval. CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N)

cvss

Technical severity, 0–10. One row per scoring source.

5.3

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 3.5–5.3

v2.03.5lowAV:N/AC:M/Au:S/C:P/I:N/A:Nprimary · NVD / NIST USexploitability 6.8 · impact 2.9

v3.15.3mediumCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:Nprimary · NVD / NIST USexploitability 1.6 · impact 3.6

v3.15.3mediumCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:Nsecondary · OSV

v3.14.9mediumCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-254US

affected products (3)

Products and version ranges known to be affected.

Tinfoil devise-two-factor≤ < 4.0.2enisa_euvdEU
tinfoilsecurity devise-two-factor< 4.0.2nvdUScpe:2.3:a:tinfoilsecurity:devise-two-factor:*:*:*:*:*:*:*:*
RubyGems devise-two-factor< 4.0.2osvUSpkg:gem/devise-two-factor

advisories (1)

Vendor and ecosystem advisories describing this.

GHSA-jm35-h8q2-73mpImproper one time password handling in devise-two-factor2022-04-07ghsa · osvUS
### Impact As a result of an incomplete fix for CVE-2015-7225, in versions of devise-two-factor prior to 4.0.2 it is possible to reuse a One-Time-Password (OTP) for one (and only one) immediately trailing interval. ### Patches This vulnerability has been patched in version 4.0.2 which was released on March 24th, 2022. Individuals using this package are strongly encouraged to upgrade as soon as possible. ### Credit for discovery Benoit Côté-Jodoin Michael Nipper - https://github.com/tinfoil/devise-two-factor/issues/106

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd nvd osv NVD CVE.org MITRE

published 2022-04-11modified 2026-06-17

references (5)

External citations — patches, advisories, analysis.

scry

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