Omni manages Kubernetes on bare metal, virtual machines, or in a cloud. Prior to 1.6.6 and from 1.7.0 until 1.7.3, SAML.getSession in internal/pkg/auth/interceptor/saml.go checks SAMLAssertion.Used and marks it used in separate state operations. Concurrent requests carrying the same captured saml-session token can each observe the assertion as unused and obtain authentication as the victim before either update is visible. The attacker can invoke SAML-protected gRPC endpoints, use ConfirmPublicKey to create multiple persistent credentials tied to the victim, and generate audit entries attributed to the victim, with the resulting access potentially affecting confidentiality, integrity, and availability according to the victim's privileges. This issue is fixed in versions 1.6.6 and 1.7.3.
https://github.com/siderolabs/omni/security/advisories/GHSA-5x9f-6vg5-qg4m
https://github.com/siderolabs/omni/releases/tag/v1.7.3
https://github.com/siderolabs/omni/releases/tag/v1.6.6
https://github.com/siderolabs/omni/pull/2816
https://github.com/siderolabs/omni/commit/ced79da6c032d2103803eb53343d0916cc957d2a
https://github.com/siderolabs/omni/commit/4c4c1e2d8226914f26774a309a91595f168ee921
https://github.com/siderolabs/omni/commit/272d3f4dd00e778b39fde09afde35575fe13ef13