In Saml2 Authentication Services for ASP.NET versions before 1.0.2, and between 2.0.0 and 2.6.0, there is a vulnerability in how tokens are validated in some cases. Saml2 tokens are usually used as bearer tokens - a caller that presents a token is assumed to be the subject of the token. There is also support in the Saml2 protocol for issuing tokens that is tied to a subject through other means, e.g. holder-of-key where possession of a private key must be proved. The Sustainsys.Saml2 library incorrectly treats all incoming tokens as bearer tokens, even though they have another subject confirmation method specified. This could be used by an attacker that could get access to Saml2 tokens with another subject confirmation method than bearer. The attacker could then use such a token to create a log in session. This vulnerability is patched in versions 1.0.2 and 2.7.0.
The requirements for the product dictate the use of an established authentication algorithm, but the implementation of the algorithm is incorrect.
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
| Link | Tags |
|---|---|
| https://github.com/Sustainsys/Saml2/commit/e58e0a1aff2b1ead6aca080b7cdced55ee6d5241 | third party advisory patch |
| https://github.com/Sustainsys/Saml2/security/advisories/GHSA-9475-xg6m-j7pw | mitigation third party advisory |
| https://github.com/Sustainsys/Saml2/issues/712 | third party advisory |
| https://www.nuget.org/packages/Sustainsys.Saml2/ | third party advisory |