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Build Of QuarkusApplication · Redhat

CVE-2023-1664

MEDIUM · 6.5 CVSS v3.1 Published 2023-05-26
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
74/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A flaw was found in Keycloak. This flaw depends on a non-default configuration "Revalidate Client Certificate" to be enabled and the reverse proxy is not validating the certificate before Keycloak. Using this method an attacker may choose the certificate which will be validated by the server. If this happens and the KC_SPI_TRUSTSTORE_FILE_FILE variable is missing/misconfigured, any trustfile may be accepted with the logging information of "Cannot validate client certificate trust: Truststore not available". This may not impact availability as the attacker would have no access to the server, but consumer applications Integrity or Confidentiality may be impacted considering a possible access to them. Considering the environment is correctly set to use "Revalidate Client Certificate" this flaw is avoidable.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

In Keycloak with 'Revalidate Client Certificate' enabled, if the reverse proxy doesn't validate client certificates before forwarding to Keycloak AND the KC_SPI_TRUSTSTORE_FILE_FILE variable is missing or misconfigured, the server accepts any client certificate. The vulnerability manifests with the log message 'Cannot validate client certificate trust: Truststore not available', potentially allowing an attacker to bypass client certificate validation and gain unauthorized access to consumer applications.

MitigationEnsure KC_SPI_TRUSTSTORE_FILE_FILE is properly configured when using client certificate revalidation, and configure the reverse proxy to validate client certificates before forwarding requests to Keycloak.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Build Of QuarkusApplication
Affected:all versions
Jboss A MqApplication
Affected:= 7
KeycloakApplication
Affected:all versions
Migration Toolkit For RuntimesApplication
Affected:all versions
Single Sign OnApplication
Affected:= 7.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm Keycloak or RH-SSO installation
    Identify if Keycloak or Red Hat Single Sign-On is deployed in the environment. Check for process listening on port 8080/8443, or search for keycloak/jboss binaries, or check /opt/keycloak or similar installation directories.
    Affected if Keycloak or RH-SSO 7.0 is present in the environment
  2. Verify if Revalidate Client Certificate is enabled
    Inspect the Keycloak startup configuration or realm settings. Look for 'Revalidate Client Certificate' option in the realm's authentication flows, or search configuration files for related client-certificate validation settings.
    Affected if 'Revalidate Client Certificate' or equivalent client certificate revalidation is enabled in any authentication flow
  3. Check KC_SPI_TRUSTSTORE_FILE_FILE configuration
    Review Keycloak environment variables or startup scripts. Search for KC_SPI_TRUSTSTORE_FILE_FILE variable in shell scripts, systemd service files, or kubernetes/secrets configurations. Verify if it points to a valid truststore file.
    Affected if KC_SPI_TRUSTSTORE_FILE_FILE is unset, empty, or points to a non-existent file
  4. Search for the vulnerability log signature
    Search Keycloak server logs for the string 'Cannot validate client certificate trust: Truststore not available'. Check current and archived log files.
    Affected if This log message appears in Keycloak server logs
  5. Verify reverse proxy client certificate validation
    Review the reverse proxy (nginx, apache, haproxy, etc.) configuration in front of Keycloak. Check if it is configured to verify and forward client certificates using 'ssl_verify_client' or equivalent directive.
    Affected if The reverse proxy is not configured to validate client certificates before forwarding requests to Keycloak

A user is affected if Keycloak/RH-SSO is running with Revalidate Client Certificate enabled, the truststore file is not properly configured via KC_SPI_TRUSTSTORE_FILE_FILE, AND the reverse proxy does not validate client certificates before forwarding, resulting in the truststore error log.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Ensure KC_SPI_TRUSTSTORE_FILE_FILE is properly configured when using client certificate revalidation, and configure the reverse proxy to validate client certificates before forwarding requests to Keycloak.

Recommended fix Moderate confidence
  1. 1. Review the Keycloak configuration to determine if 'Revalidate Client Certificate' is enabled.
  2. 2. If 'Revalidate Client Certificate' is enabled, ensure the KC_SPI_TRUSTSTORE_FILE environment variable is properly set to point to a valid truststore file.
  3. 3. Verify that the truststore contains the necessary CA certificates needed to validate client certificates.
  4. 4. Alternatively, configure the reverse proxy (e.g., Apache, Nginx) to validate client certificates BEFORE forwarding requests to Keycloak, ensuring the proxy performs proper certificate validation.
  5. 5. Ensure the KC_SPI_TRUSTSTORE_FILE_PASSWORD environment variable is set correctly if the truststore is password-protected.
  6. 6. After configuration changes, restart the Keycloak service and verify the logging no longer shows 'Cannot validate client certificate trust: Truststore not available'.
  7. 7. Test the client certificate validation to ensure only trusted certificates are accepted.

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Build Of Quarkus Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-1664 in production — separate from our analysis above.

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