Executive brief
A vulnerability in the Hubuum Rust client library allows certain network requests to bypass security controls like proxies or audit logs. This occurs when the library uses its default connection method instead of a developer-configured custom transport for sensitive tasks like logging in or validating tokens. As a result, login credentials or security tokens could be sent over unintended network paths, potentially exposing them to unauthorized monitoring or violating corporate security policies.
Technical details
A protection mechanism failure (CWE-693) exists in hubuum_client versions 0.3.0 through 0.6.0. When a developer configures a custom transport via ClientBuilder::with_transport, several operations—including password login, bearer-token validation, and health probes—incorrectly default to the internal reqwest client. This bypasses user-defined security boundaries such as proxy enforcement, request signing, and audit logging. An attacker monitoring the network could potentially capture plaintext credentials or bearer tokens sent outside the intended secure transport. The issue is fixed in version 0.6.1, which also disables automatic redirect following as a defense-in-depth measure.
Affected products
- hubuum hubuum_client >= 0.3.0, <= 0.6.0
Timeline
- 2026-07-23: disclosed
- 2026-07-23: patched: Version 0.6.1 released
- 2026-07-24: advisory
References
- https://github.com/hubuum/hubuum-client-rust/security/advisories/GHSA-qqc3-94qv-7fw3
- https://github.com/hubuum/hubuum-client-rust/commit/5a5c275ffa45f342459b7d3e977926da643bde50
- https://github.com/hubuum/hubuum-client-rust/releases/tag/v0.6.1
- https://api.github.com/repos/hubuum/hubuum-client-rust/security-advisories/GHSA-qqc3-94qv-7fw3