# CVE-2020-5261: Missing Token Replay Detection in Saml2 Authentication services for ASP.NET

Source: https://junglewise.ai/threats/cve-2020-5261-missing-token-replay-detection-in-saml2-authentication-services  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2020-03-25  
License: CC BY 4.0 with a link back

CVE-2020-5261 · Severity: low · CVSS 3.1 · Published 2020-03-25

Missing Token Replay Detection in Saml2 Authentication services for ASP.NET

Technologies: [Sustainsys.Saml2 (NuGet)](https://junglewise.ai/threats/technologies/sustainsys-saml2). Vendors: [NuGet](https://junglewise.ai/threats/vendors/nuget).

## Quick answers

**Is CVE-2020-5261 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2020-5261 being exploited in the wild.

**How severe is CVE-2020-5261?** Low severity, with a CVSS score of 3.1, published 25 March 2020.

**Which products and versions are affected?** Sustainsys.Saml2 (NuGet) ECOSYSTEM:introduced=2.0.0,fixed=2.5.0.

**Is there a fix for CVE-2020-5261?** Yes. Sustainsys.Saml2 (NuGet): upgrade to 2.5.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2020-5261?** Check whether you run Sustainsys.Saml2 (NuGet) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Sustainsys.Saml2 (NuGet): upgrade to 2.5.0 or later

  ```sh
  dotnet add package Sustainsys.Saml2 --version 2.5.0
  ```


## Affected products

- Sustainsys.Saml2 (NuGet) ECOSYSTEM:introduced=2.0.0,fixed=2.5.0

## Identifiers

- CVE-2020-5261
- GHSA-g6j2-ch25-5mmv

## Related threats

- [Sustainsys.Saml2 Insufficient Identity Provider Issuer Validation](https://junglewise.ai/threats/cve-2023-41890-sustainsys-saml2-insufficient-identity-provider-issuer-validation)
- [Subject Confirmation Method not validated in Saml2 Authentication Services for ASP.NET](https://junglewise.ai/threats/cve-2020-5268-subject-confirmation-method-not-validated-in-saml2-authentication)