IdentityServer Open Redirect vulnerability
Impact
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.
Affected Methods
-
In the
DefaultIdentityServerInteractionService, theGetAuthorizationContextAsyncmethod may return non-null and theIsValidReturnUrlmethod may return true for malicious Urls, indicating incorrectly that they can be safely redirected to.UI code calling these two methods is the most commonly used code path that will expose the vulnerability. The default UI templates rely on this behavior in the Login, Challenge, and Consent pages. Customized user interface code might also rely on this behavior. The following uncommonly used APIs are also vulnerable:
-
The
ServerUrlExtensions.GetIdentityServerRelativeUrl,ReturnUrlParser.ParseAsyncandOidcReturnUrlParser.ParseAsyncmethods may incorrectly return non-null, and theReturnUrlParser.IsValidReturnUrlandOidcReturnUrlParser.IsValidReturnUrlmethods may incorrectly return true for malicious Urls.
Patches
IdentityServer4 is no longer supported and will not be receiving updates. Please consider updating to Duende.IdentityServer.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| .NET (NuGet) | IdentityServer4 | <= 4.1.2 | no fix |
References
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N- Weakness (CWE)
CWE-601- Platform
- .NET (NuGet)
- Package
IdentityServer4- Disclosed
- 31.07.2024
- Updated
- 11.10.2026 11:23
Sources and licenses
OSV / GitHub Advisory Database - GHSA-55p7-v223-x366 - CC BY 4.0
Vulnerability history: IdentityServer4
All published vulnerabilities of this package (.NET (NuGet)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 2
- First → latest
- 07.2024 07.2024
- Without a fix
- 2
- Exploited in attacks
- 0
Severity breakdown
- Medium 2
Disclosures per year
- 2024: 2
- 2025: 0
- 2026: 0
-
IdentityServer Open Redirect vulnerability this entry
Know which vulnerabilities affect your application
With the DockRay integration and software inventory enabled, DockRay checks reported component versions against known vulnerabilities and notifies you about confirmed matches. Coverage depends on the supported technology and available advisory data.