GHSA-5pf6-2qwx-pxm2 Go SDK for CloudEvents's use of WithRoundTripper to create a Client leaks credentials

• Go github.com/cloudevents/sdk-go/v2: < 2.15.2 → fixed in 2.15.2

Impact _What kind of vulnerability is it? Who is impacted?_ Using cloudevents.WithRoundTripper to create a cloudevents.Client with an authenticated http.RoundTripper causes the go-sdk to leak credentials to arbitrary endpoints. The relevant code is here (also inline, emphasis added): if p.Client == nil { p.Client = http.DefaultClient } if p.roundTripper != nil { p.Client.Transport = p.roundTripper } When the transport is populated with an authenticated transport such as: • oauth2.Transport • idtoken.NewClient(...).Transport ... then http.DefaultClient is modified with the authenticated transport and will start to send Authorization tokens to any endpoint it is used to contact! Found and patched by: @tcnghia and @mattmoor Patches v.2.15.2