Time-of-check Time-of-use (TOCTOU) Race Condition Affecting duende.accesstokenmanagement package, versions [,3.2.0)
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applications- Snyk IDSNYK-DOTNET-DUENDEACCESSTOKENMANAGEMENT-8732920
- published19 Feb 2025
- disclosed18 Feb 2025
- creditMichael Dimoudis
Introduced: 18 Feb 2025
CVE-2025-26620 (opens in a new tab)How to fix?
Upgrade Duende.AccessTokenManagement to version 3.2.0 or higher.
Overview
Duende.AccessTokenManagement is a library that manages OAuth access tokens in .NET workers and ASP.NET Core worker services
Affected versions of this package are vulnerable to Time-of-check Time-of-use (TOCTOU) Race Condition when handling concurrent ClientCredentialsToken requests. The HttpContext.GetClientAccessTokenAsync() and IClientCredentialsTokenManagementService.GetAccessTokenAsync() functions may return access tokens with incorrect scope, resource indicator, or other protocol parameters. An attacker can exploit this to obtain the values intended for a different request sent at the same time. This is only exploitable if custom TokenRequestParameters are allowed, overriding one of the above functions.