CVE-2021-3513Network attack vector

Password confirmation via locked-account error distinction

Published Aug 22, 2022 · Updated Aug 3, 2024

Information disclosure in Keycloak before 13.0.0 allows remote attackers to confirm valid passwords after permanent account lockout. The login flow returns an account-disabled response when a locked account receives the correct password instead of the generic invalid-credentials response. Permanent brute-force lockout must be enabled and the target account locked; repeated unauthenticated login attempts can then reveal a working credential without granting a session.

CVSS severity7.5
High
EPSS probability0.78%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Keycloak before 13.0.0 allows remote attackers to confirm valid passwords after permanent account lockout. The login flow returns an account-disabled response when a locked account receives the correct password instead of the generic invalid-credentials response. Permanent brute-force lockout must be enabled and the target account locked; repeated unauthenticated login attempts can then reveal a working credential without granting a session.

The record

CVE
CVE-2021-3513
Published
Aug 22, 2022
Updated
Aug 3, 2024
Vendor
Keycloak
Product
Keycloak
Classifications
CWE-209, T1110.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 22, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Fixed in keycloak v13.0.0.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Keycloak · Keycloakversion=Fixed in keycloak v13.0.0.

Published CVSS scores

7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-209Generation of Error Message Containing Sensitive Information
T1110.001Password Guessing

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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