Insufficient Nonce Validation in Eclipse Milo Client
### Impact
Credential replay affecting those connected to a server when *all 3* of the following conditions are met:
- `SecurityPolicy` is `None`
- using username/password or X509-based authentication
- the server has a defect causing it to send null/empty or zeroed nonces
### Patches
The problem has been patched in version `0.3.6`. A more relaxed treatment of validation as agreed upon by the OPC UA Security Working Group is implemented in version `0.3.7`.
### Workarounds
Do not use username/password or X509-based authentication with `SecurityPolicy` of `None`.
### References
https://opcfoundation.org/SecurityBulletins/OPC%20Foundation%20Security%20Bulletin%20CVE-2019-19135.pdf
### For more information
If you have any questions or comments about this advisory:
* Open an issue at
https://github.com/eclipse/milo/issues https://github.com/eclipse/milo/issues
* Email [the mailing list](mailto:milo-dev@eclipse.org)