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

Summary

Steeltoe is an open source project that provides a collection of libraries that helps users build cloud-native applications. In Steeltoe.Management.Endpoint prior to version 4.2.0 and Steeltoe.Management.EndpointCore prior to version 3.4.0, 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. Steeltoe.Management.Endpoint 4.2.0 and Steeltoe.Management.EndpointCore 3.4.0 patch the issue. 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; and/or require authorization on actuator endpoints.

Timeline

1. Jun 17, 2026, 9:44 PM UTCCVE published
2. Jun 18, 2026, 3:44 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: yes · Technical impact: partial

3. Jun 18, 2026, 3:45 PM UTCRecord last updated

Affected versions

• SteeltoeOSS Steeltoe.Management.Endpoint

  fixed in 4.2.0

• SteeltoeOSS Steeltoe.Management.EndpointCore

  fixed in 3.4.0

• Steeltoe.Management.EndpointNuGet

  fixed in 4.2.0

• Steeltoe.Management.EndpointCoreNuGet

  fixed in 3.4.0

References 3