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Insufficient Identity Provider Issuer Validation

High
AndersAbel published GHSA-fv2h-753j-9g39 Sep 19, 2023

Package

nuget Kentor.AuthServices (NuGet)

Affected versions

All Versions

Patched versions

N/A
nuget Sustainsys.Saml2 (NuGet)
< 1.0.3
2.0.0-2.9.1
1.0.3
2.9.2

Description

Impact

When a response is processed, the issuer of the Identity Provider is not sufficiently validated. This could allow a malicious identity provider to craft a Saml2 response that is processed as if issued by another identity provider. It is also possible for a malicious end user to cause stored state intended for one identity provider to be used when processing the response from another provider.

An application is impacted if they rely on any of these features in their authentication/authorization logic:

  • the issuer of the generated identity and claims
  • items in the stored request state (AuthenticationProperties)

Patches

Patched in version 2.9.2 and 1.0.3. All previous versions are vulnerable.

Workarounds

The AcsCommandResultCreated notification can be used to add the validation required if an upgrade to patched packages is not possible.

References

The patch is linked to #712 and #713

Severity

High

CVE ID

CVE-2023-41890

Weaknesses

Authentication Bypass by Alternate Name

The product performs authentication based on the name of a resource being accessed, or the name of the actor performing the access, but it does not properly check all possible names for that resource or actor. Learn more on MITRE.

Authentication Bypass by Capture-replay

A capture-replay flaw exists when the design of the product makes it possible for a malicious user to sniff network traffic and bypass authentication by replaying it to the server in question to the same effect as the original message (or with minor changes). Learn more on MITRE.

Credits