Steeltoe's env sanitizer misses connection strings — leaks embedded DB passwords

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:<name> or Steeltoe Connectors' Steeltoe:Client:<type>: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.