CVE-2025-53013 Information

Description

Himmelblau is an interoperability suite for Microsoft Azure Entra ID and Intune. A vulnerability present in versions 0.9.10 through 0.9.16 allows a user to authenticate to a Linux host via Himmelblau using an invalid Linux Hello PIN provided the host is offline. While the user gains access to the local system Single Sign-On (SSO) fails due to the network being down and the inability to issue tokens (due to a failure to unlock the Hello key). The core issue lies in an incorrect assumption within the acquire_token_by_hello_for_business_key function: it was expected to return a TPMFail error for an invalid Hello key when offline but instead a preceding nonce request resulted in a RequestFailed error leading the system to erroneously transition to an offline success state without validating the Hello key unlock. This impacts systems using Himmelblau for authentication when operating in an offline state with Hello PIN authentication enabled. Rocky Linux 8 (and variants) are not affected by this vulnerability. The problem is resolved in Himmelblau version 0.9.17. A workaround is available for users who cannot immediately upgrade. Disabling Hello PIN authentication by setting enable_hello = false in /etc/himmelblau/himmelblau.conf will mitigate the vulnerability.

Reference

https://github.com/himmelblau-idm/himmelblau/commit/64b03739f1d5ee472b1cff3ed20ed9af1c65a6f8 https://github.com/himmelblau-idm/himmelblau/commit/78477d684df710d57c10091c87b92665cfac98ae https://github.com/himmelblau-idm/himmelblau/security/advisories/GHSA-j93j-pwm6-p97j

Related CNNVD

CNNVD-202506-3349 (Published: 2025-06-26)