Is CVE-2019-5421 actively exploited?

No active exploitation of CVE-2019-5421 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2019-5421 be exploited remotely?

Yes. CVE-2019-5421 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2019-5421?

CVE-2019-5421 has a CVSS score of 9.8 (CRITICAL).

HOME VULNERABILITIESCVE-2019-5421

CRITICAL

CVE-2019-5421

CWE-367Published: April 3, 2019· Updated: Jun 17, 2026

9.8

CVSS v3.1

Official Description

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.

NVD Source

Technical Analysis

CVE-2019-5421 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.