ZITADEL, open source authentication management software, uses Go templates to render the login UI. Under certain circumstances an action could set reserved claims managed by ZITADEL. For example it would be possible to set the claim `urn:zitadel:iam:user:resourceowner:name`. To compensate for this we introduced a protection that does prevent actions from changing claims that start with `urn:zitadel:iam`. This vulnerability is fixed in 2.48.3, 2.47.8, 2.46.5, 2.45.5, 2.44.7, 2.43.11, and 2.42.17.

Affected: Go: github.com/zitadel/zitadel

### Impact Under certain circumstances an action could set [reserved claims](https://zitadel.com/docs/apis/openidoauth/claims#reserved-claims) managed by ZITADEL.

For example it would be possible to set the claim `urn:zitadel:iam:user:resourceowner:name`

```json {"urn:zitadel:iam:user:resourceowner:name": "ACME"} ```

if it was not set by ZITADEL itself.

To compensate for this we introduced a protection that does prevent actions from changing claims that start with `urn:zitadel:iam`

### Patches 2.x versions are fixed on >= [2.48.3](https://github.com/zitadel/zitadel/releases/tag/v2.48.3) 2.47.x versions are fixed on >= [2.47.8](https://github.com/zitadel/zitadel/releases/tag/v2.47.8) 2.46.x versions are fixed on >= [2.46.5](https://github.com/zitadel/zitadel/releases/tag/v2.46.5) 2.45.x versions are fixed on >= [2.45.5](https://github.com/zitadel/zitadel/releases/tag/v2.45.5) 2.44.x versions are fixed on >= [2.44.7](https://github.com/zitadel/zitadel/releases/tag/v2.44.7) 2.43.x versions are fixed on >= [2.43.11](https://github.com/zitadel/zitadel/releases/tag/v2.43.11) 2.42.x versions are fixed on >= [2.42.17](https://github.com/zitadel/zitadel/releases/tag/v2.42.17)

### Workarounds No workaround available since a patch is available

### Credits Many thanks to @schettn whose disclosure of another topic lead us to find this issue.