CVE-2024-39694: Duende IdentityServer is an OpenID Connect and OAuth 2.x framework for ASP.NET Core. It is possible for an attacker to craft malicious Urls that certa...

Description

Duende IdentityServer is an OpenID Connect and OAuth 2.x framework for ASP.NET Core. It is possible for an attacker to craft malicious Urls that certain functions in IdentityServer will incorrectly treat as local and trusted. If such a Url is returned as a redirect, some browsers will follow it to a third-party, untrusted site. Note: by itself, this vulnerability does **not** allow an attacker to obtain user credentials, authorization codes, access tokens, refresh tokens, or identity tokens. An attacker could however exploit this vulnerability as part of a phishing attack designed to steal user credentials. This vulnerability is fixed in 7.0.6, 6.3.10, 6.2.5, 6.1.8, and 6.0.5. Duende.IdentityServer 5.1 and earlier and all versions of IdentityServer4 are no longer supported and will not be receiving updates. If upgrading is not possible, use `IUrlHelper.IsLocalUrl` from ASP.NET Core to validate return Urls in user interface code in the IdentityServer host.

Metrics

CVSS 3.1

4.7/10

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

EPSS Probability

0.50%

39.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-601

References

Timeline

Published: Jul 31, 2024
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2024-39694?

Duende IdentityServer is an OpenID Connect and OAuth 2.x framework for ASP.NET Core. It is possible for an attacker to craft malicious Urls that certain functions in IdentityServer will incorrectly treat as local and trusted. If such a Url is returned as a redirect, some browsers will follow it to a third-party, untrusted site. Note: by itself, this vulnerability does **not** allow an attacker to obtain user credentials, authorization codes, access tokens, refresh tokens, or identity tokens. An attacker could however exploit this vulnerability as part of a phishing attack designed to steal user credentials. This vulnerability is fixed in 7.0.6, 6.3.10, 6.2.5, 6.1.8, and 6.0.5. Duende.IdentityServer 5.1 and earlier and all versions of IdentityServer4 are no longer supported and will not be receiving updates. If upgrading is not possible, use `IUrlHelper.IsLocalUrl` from ASP.NET Core to validate return Urls in user interface code in the IdentityServer host.

How severe is CVE-2024-39694?

CVE-2024-39694 has a CVSS score of 4.7/10 (MEDIUM severity). The EPSS model estimates a 0.50% probability of exploitation in the next 30 days.

How do I fix CVE-2024-39694?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.