Summary
Keycloak vulnerable to user impersonation via stolen UUID code
Keycloak's OpenID Connect user authentication was found to incorrectly authenticate requests. An authenticated attacker who could also obtain a certain piece of info from a user request, from a victim within the same realm, could use that data to impersonate the victim and generate new session tokens.
Impact
The application does not adequately verify the identity of a user, device, or process before granting access. Typical impact: unauthorized access to functions or data reserved for authenticated parties.
CVE-2023-0264 has a CVSS score of 8.7 (High). The vector is network-reachable, low privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (21.0.1); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2023-0264? CVE-2023-0264 is a high-severity improper authentication vulnerability in org.keycloak:keycloak-services (maven), affecting versions < 21.0.1. It is fixed in 21.0.1. The application does not adequately verify the identity of a user, device, or process before granting access.
- How severe is CVE-2023-0264? CVE-2023-0264 has a CVSS score of 8.7 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of org.keycloak:keycloak-services are affected by CVE-2023-0264? org.keycloak:keycloak-services (maven) versions < 21.0.1 is affected.
- Is there a fix for CVE-2023-0264? Yes. CVE-2023-0264 is fixed in 21.0.1. Upgrade to this version or later.
- Is CVE-2023-0264 exploitable, and should I be worried? Whether CVE-2023-0264 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2023-0264 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2023-0264? Upgrade
org.keycloak:keycloak-servicesto 21.0.1 or later.