CVE-2023-45669

WebAuthn4J Spring Security Improper signature counter value handling

Improper signature counter value handling

References

For more details about WebAuthn signature counters, see WebAuthn specification 6.1.1. Signature Counter Considerations.

Reporter

This issue was discovered by Michael Budnick (@mbudnick)

A flaw was found in webauthn4j-spring-security-core. When an authneticator returns an incremented signature counter value during authentication, webauthn4j-spring-security-core does not properly persist the value, which means cloned authenticator detection does not work.
An attacker who cloned valid authenticator in some way can use the cloned authenticator without being detected.

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-2023-45669 has a CVSS score of 4.8 (Medium). The vector is network-reachable, no privileges required, and no user interaction. 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 (0.9.1.RELEASE); upgrading removes the vulnerable code path.

Kodem intelligence

Already deployed Kodem?

Please upgrade to com.webauthn4j:webauthn4j-spring-security-core:0.9.1.RELEASE

1. What is CVE-2023-45669? CVE-2023-45669 is a medium-severity improper authentication vulnerability in com.webauthn4j:webauthn4j-spring-security-core (maven), affecting versions < 0.9.1.RELEASE. It is fixed in 0.9.1.RELEASE. The application does not adequately verify the identity of a user, device, or process before granting access.
2. How severe is CVE-2023-45669? CVE-2023-45669 has a CVSS score of 4.8 (Medium). 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.
3. Which versions of com.webauthn4j:webauthn4j-spring-security-core are affected by CVE-2023-45669? com.webauthn4j:webauthn4j-spring-security-core (maven) versions < 0.9.1.RELEASE is affected.
4. Is there a fix for CVE-2023-45669? Yes. CVE-2023-45669 is fixed in 0.9.1.RELEASE. Upgrade to this version or later.
5. Is CVE-2023-45669 exploitable, and should I be worried? Whether CVE-2023-45669 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
6. What actually determines whether CVE-2023-45669 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.
7. How do I fix CVE-2023-45669? Upgrade com.webauthn4j:webauthn4j-spring-security-core to 0.9.1.RELEASE or later.