GHSA-q62h-354g-5r85 Steeltoe's env sanitizer misses connection strings — leaks embedded DB passwords

• NuGet Steeltoe.Management.Endpoint: < 4.2.0 → fixed in 4.2.0 • NuGet Steeltoe.Management.EndpointCore: < 3.4.0 → fixed in 3.4.0

Summary The `Sanitizer` component in the Environment actuator redacts configuration values by matching the configuration key name against a suffix list. The default list (`password`, `secret`, `key`, `token`, `.*credentials.*`, `vcap_services`) does not cover the standard .NET pattern `ConnectionStrings:` or Steeltoe Connectors' `Steeltoe:Client::Default:ConnectionString`. There is no value-based scrubbing, so full connection string values including embedded `Password=` and `user:pass@host` segments are returned verbatim in `/actuator/env` responses. Impact Any caller who can reach `/actuator/env` can receive connection strings containing plaintext credentials. Those credentials enable direct connection to the backing database, bypassing the application tier. Affected configuration • Application configuration contains credentials in `ConnectionStrings:*` or `*:ConnectionString` keys. • On standard deployments: `env` is added to `Management:Endpoints:Actuator:Exposure:Include`. This is not the default. • On Cloud Foundry: the `/cloudfoundryapplication/env` path is accessible to any authenticated CF user with `read_basic_data` permissions (Space Auditor and above) regardless of the exposure configuration. Mitigations If an immediate upgrade is not possible: • On the standard path, remove `env` from the actuator exposure list. • Add `.*connectionstring.*` to `KeysToSanitize` as a defense-in-depth measure for both paths. • Require authorization on actuator endpoints.