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Fencer Vulns
critical 9.8

CVE-2019-5421 json

devise Time-of-check Time-of-use Race Condition vulnerability

published 2019-03-19 7 y ago modified 2026-06-17 4 mo ago also GHSA-73rf-6mrf-759q , EUVD-2019-0372

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.6%
EPSS 1.6% chance of exploitation in 30 days, percentile 75%
public exploits
0
none known

Summary

Plataformatec Devise version 4.5.0 and earlier, using the lockable module contains a CWE-367 vulnerability in The `Devise::Models::Lockable` class, more specifically at the `#increment_failed_attempts` method. File location: lib/devise/models/lockable.rb that can result in Multiple concurrent requests can prevent an attacker from being blocked on brute force attacks. This attack appear to be exploitable via Network connectivity - brute force attacks. This vulnerability appears to have been fixed in 4.6.0 and later.

Patch / fix

  • rubygems devise 4.6.0
  • ruby-devise Debian 12 4.5.0-3

debian advisories DEBIAN-CVE-2019-5421

  • ruby-devise Ubuntu 20.04 LTS 4.5.0-3

ubuntu advisories UBUNTU-CVE-2019-5421

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Exploit prediction

1.56% chance of exploitation in the next 30 days, higher than 75% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/plataformatec/devise/issues/4981 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P

Affected packages

ecosystem package affected fixed in
rubygems devise
<4.6.0
4.6.0

Affected products

  • Plataformatec Devise ruby gem

Classification

Weakness
  • CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition
  • CWE-307 Improper Restriction of Excessive Authentication Attempts

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.