CVE-2023-40178

The lack of checking of current timestamp allows a LogoutRequest XML to be reused multiple times even when the current time is past the NotOnOrAfter.

Details

It was noticed that in the validatePostRequestAsync() flow in saml.js, the current timestamp is never checked. This could present a vulnerability where a user who has an XML LogoutRequest could validated it if the IssueInstance and the NotOnOrAfter are valid along with valid credentials (signature, certificate etc.).

PoC

I was able to validate a sample valid LogoutRequest XML multiple times through postman by sending it to my endpoint regardless if the current present time was past the NotOnOrAfter time. After some further testing, it seems that only the IssueInstance is checked against NotOnOrAfter. Not sure if this was the intended behaviour but I believe having a never expiring valid LogoutRequest could be dangerous.

This could impact the user where they would be logged out from an expired LogoutRequest. In bigger contexts, if LogoutRequests are sent out in mass to different SPs, this could impact many users on a large scale.

CVE-2023-40178 has a CVSS score of 5.3 (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 (4.0.5); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2023-40178? CVE-2023-40178 is a medium-severity security vulnerability in @node-saml/node-saml (npm), affecting versions < 4.0.5. It is fixed in 4.0.5.
2. How severe is CVE-2023-40178? CVE-2023-40178 has a CVSS score of 5.3 (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 @node-saml/node-saml are affected by CVE-2023-40178? @node-saml/node-saml (npm) versions < 4.0.5 is affected.
4. Is there a fix for CVE-2023-40178? Yes. CVE-2023-40178 is fixed in 4.0.5. Upgrade to this version or later.
5. Is CVE-2023-40178 exploitable, and should I be worried? Whether CVE-2023-40178 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-2023-40178 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-2023-40178? Upgrade @node-saml/node-saml to 4.0.5 or later.