Duende IdentityServer Open Redirect vulnerability
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Spoofing
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-601.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| DuendeSoftware | IdentityServer | before 6.0.5; 6.1.0-preview.1 – 6.1.7; 6.2.0-preview.1 – 6.2.4; 6.3.0-preview.1 – 6.3.9; 7.0.0-preview.1 – 7.0.5 | 6.0.5 | Patch available | CNA |
| — | Duende.IdentityServer (NuGet) | 7.0.0-preview.1 to before 7.0.6 | 7.0.6 | Patch available | GHSA-ff4q-64jc-gx98 |
| — | Duende.IdentityServer (NuGet) | 6.3.0-preview.1 to before 6.3.10 | 6.3.10 | Patch available | GHSA-ff4q-64jc-gx98 |
| — | Duende.IdentityServer (NuGet) | 6.2.0-preview.1 to before 6.2.5 | 6.2.5 | Patch available | GHSA-ff4q-64jc-gx98 |
| — | Duende.IdentityServer (NuGet) | 6.1.0-preview.1 to before 6.1.8 | 6.1.8 | Patch available | GHSA-ff4q-64jc-gx98 |
| — | Duende.IdentityServer (NuGet) | 6.0.0-preview.1 to before 6.0.5 | 6.0.5 | Patch available | GHSA-ff4q-64jc-gx98 |
| — | IdentityServer4 (NuGet) | up to 4.1.2 | — | No fix listed | GHSA-ff4q-64jc-gx98 |
- IdentityServer VendorDuendeSoftware Affected before 6.0.5; 6.1.0-preview.1 – 6.1.7; 6.2.0-preview.1 – 6.2.4; 6.3.0-preview.1 – 6.3.9; 7.0.0-preview.1 – 7.0.5 Fixed in 6.0.5 Patch available CNA
- Duende.IdentityServer (NuGet) Vendor— Affected 7.0.0-preview.1 to before 7.0.6 Fixed in 7.0.6 Patch available GHSA-ff4q-64jc-gx98
- Duende.IdentityServer (NuGet) Vendor— Affected 6.3.0-preview.1 to before 6.3.10 Fixed in 6.3.10 Patch available GHSA-ff4q-64jc-gx98
- Duende.IdentityServer (NuGet) Vendor— Affected 6.2.0-preview.1 to before 6.2.5 Fixed in 6.2.5 Patch available GHSA-ff4q-64jc-gx98
- Duende.IdentityServer (NuGet) Vendor— Affected 6.1.0-preview.1 to before 6.1.8 Fixed in 6.1.8 Patch available GHSA-ff4q-64jc-gx98
- Duende.IdentityServer (NuGet) Vendor— Affected 6.0.0-preview.1 to before 6.0.5 Fixed in 6.0.5 Patch available GHSA-ff4q-64jc-gx98
- IdentityServer4 (NuGet) Vendor— Affected up to 4.1.2 Fixed in — No fix listed GHSA-ff4q-64jc-gx98
Remediation
- Fix · CNA IdentityServer (DuendeSoftware) Fixed in 6.0.5
- Fix · GHSA-ff4q-64jc-gx98 Duende.IdentityServer (NuGet) Fixed in 7.0.6 Advisory →
- Fix · GHSA-ff4q-64jc-gx98 Duende.IdentityServer (NuGet) Fixed in 6.3.10 Advisory →
- Fix · GHSA-ff4q-64jc-gx98 Duende.IdentityServer (NuGet) Fixed in 6.2.5 Advisory →
- Fix · GHSA-ff4q-64jc-gx98 Duende.IdentityServer (NuGet) Fixed in 6.1.8 Advisory →
- Fix · GHSA-ff4q-64jc-gx98 Duende.IdentityServer (NuGet) Fixed in 6.0.5 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2024-39694
- 2026-10-03 Alias added: GHSA-ff4q-64jc-gx98
References
Other 8
- https://github.com/DuendeSoftware/IdentityServer/security/advisories/GHSA-ff4q-64jc-gx98
- https://github.com/DuendeSoftware/IdentityServer/commit/269ca2171fe1e901c87f2f0797bbc7c230db87c6
- https://github.com/DuendeSoftware/IdentityServer/commit/765116a2d4fb0671b6eba015e698533900c61c8e
- https://github.com/DuendeSoftware/IdentityServer/commit/d0d8eab35ad9183b14925496803ed8b36658d0a1
- https://github.com/DuendeSoftware/IdentityServer/commit/f04cf0be859b93f43563f8f812eb92206ad94011
- https://github.com/DuendeSoftware/IdentityServer/commit/fe817b499933d6ed6141b153492d7335c28b184a
- https://github.com/IdentityServer/IdentityServer4/security/advisories/GHSA-55p7-v223-x366
- https://github.com/DuendeSoftware/IdentityServer
More DuendeSoftware vulnerabilities
- TI-2025-19557 Duende.AccessTokenManagement race condition when concurrently retrieving customized Client Credentials Access Tokens CVSS 4.0MEDIUM 6.3
- TI-2024-34875 HTTP Client uses incorrect token after refresh in Duende.AccessTokenManagement.OpenIdConnect CVSS 3.1MEDIUM 5.4
- TI-2024-33222 Duende IdentityServer has insufficient validation of DPoP cnf claim in Local APIs CVSS 3.1LOW 3.1
Sources
- CVE-2024-39694 · CVE Program
- CVE-2024-39694 · NVD
- FIRST EPSS
- GHSA-ff4q-64jc-gx98 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences