How severe is GHSA-ff4q-64jc-gx98?

GHSA-ff4q-64jc-gx98 has a CVSS score of 4.7/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-ff4q-64jc-gx98?

GHSA-ff4q-64jc-gx98 affects the following packages: Duende.IdentityServer (NuGet), Duende.IdentityServer (NuGet), Duende.IdentityServer (NuGet), Duende.IdentityServer (NuGet), Duende.IdentityServer (NuGet), IdentityServer4 (NuGet). Ecosystems affected: NuGet.

How do I fix GHSA-ff4q-64jc-gx98?

Update Duende.IdentityServer to 7.0.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-ff4q-64jc-gx98 is resolved across your whole dependency graph.

How do I detect GHSA-ff4q-64jc-gx98 in my NuGet dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Duende.IdentityServer. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-ff4q-64jc-gx98 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-ff4q-64jc-gx98?

O3 pinpoints whether GHSA-ff4q-64jc-gx98 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-ff4q-64jc-gx98 actively exploited in the wild?

No public exploit code has been indexed for GHSA-ff4q-64jc-gx98 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-ff4q-64jc-gx98?

GHSA-ff4q-64jc-gx98 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 39th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-ff4q-64jc-gx98?

GHSA-ff4q-64jc-gx98 is classified as Open Redirect (CWE-601). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-ff4q-64jc-gx98 published, and has it been updated?

GHSA-ff4q-64jc-gx98 was published on July 31, 2024 and was last updated on July 31, 2024. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

.NET NuGet

GHSA-ff4q-64jc-gx98

MEDIUM

IdentityServer Open Redirect vulnerability

Also known asCVE-2024-39694

Published

Jul 31, 2024

Updated

Jul 31, 2024

Affected

6 pkgs

Patched

5 / 6

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk39th percentile+0.36%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

6 pkgs affected

.NETDuende.IdentityServer.NETDuende.IdentityServer.NETDuende.IdentityServer.NETDuende.IdentityServer.NETDuende.IdentityServer.NETIdentityServer4

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.

Description

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.

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.

Affected Methods

In the DefaultIdentityServerInteractionService, the GetAuthorizationContextAsync method may return non-null and the IsValidReturnUrl method 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, Consent, and Account Creation pages. Customized user interface code might also rely on this behavior. The following uncommonly used APIs are also vulnerable:
The ServerUrlExtensions.GetIdentityServerRelativeUrl, ReturnUrlParser.ParseAsync and OidcReturnUrlParser.ParseAsync methods may incorrectly return non-null, and the ReturnUrlParser.IsValidReturnUrl and OidcReturnUrlParser.IsValidReturnUrl methods may incorrectly return true for malicious Urls.

Patches

This vulnerability is fixed in the following versions of Duende.IdentityServer:

7.0.6
6.3.10
6.2.5
6.1.8
6.0.5

Duende.IdentityServer 5.1 and earlier and all versions of IdentityServer4 are no longer supported and will not be receiving updates.

Workarounds

If upgrading is not possible, use IUrlHelper.IsLocalUrl from ASP.NET Core 5.0 or later to validate return Urls in user interface code in the IdentityServer host.

Affected Packages

6 total 5 fixed

Ecosystem	Package	Vulnerable range	Fix
.NETNuGet	`Duende.IdentityServer`	≥ 7.0.0-preview.1&&< 7.0.6	7.0.6
.NETNuGet	`Duende.IdentityServer`	≥ 6.3.0-preview.1&&< 6.3.10	6.3.10
.NETNuGet	`Duende.IdentityServer`	≥ 6.2.0-preview.1&&< 6.2.5	6.2.5
.NETNuGet	`Duende.IdentityServer`	≥ 6.1.0-preview.1&&< 6.1.8	6.1.8
.NETNuGet	`Duende.IdentityServer`	≥ 6.0.0-preview.1&&< 6.0.5	6.0.5
.NETNuGet	`IdentityServer4`	all versions	No fix

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Duende.IdentityServer. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update Duende.IdentityServer to 7.0.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-ff4q-64jc-gx98 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-ff4q-64jc-gx98 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-ff4q-64jc-gx98. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### 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. _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._ ### Affected Methods - In the `DefaultIdentityServerInt

O3 Security · Impact-Aware SCA

Is GHSA-ff4q-64jc-gx98 in your dependencies?

O3 detects GHSA-ff4q-64jc-gx98 across NuGet dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works

GHSA-ff4q-64jc-gx98

EPSS Exploitation Probability

Blast Radius

Description

Impact

Affected Methods

Patches

Workarounds

Affected Packages

Detection & mitigation playbook

Detect

Fix

Workarounds

How O3 protects you

Frequently Asked Questions

Is GHSA-ff4q-64jc-gx98 in your dependencies?