OSSA-2020-006: Live migration fails to update persistent domain XML

Date

August 25, 2020

CVE

CVE-2020-17376

Affects

  • Nova: <19.3.1, >=20.0.0 <20.3.1, ==21.0.0

Description

Tadayoshi Hosoya (NEC) and Lee Yarwood (Red Hat) reported a vulnerability in Nova live migration. By performing a soft reboot of an instance which has previously undergone live migration, a user may gain access to destination host devices that share the same paths as host devices previously referenced by the virtual machine on the source. This can include block devices that map to different Cinder volumes on the destination than the source. The risk is increased significantly in non-default configurations allowing untrusted users to initiate live migrations, so administrators may consider temporarily disabling this in policy if they cannot upgrade immediately. This only impacts deployments where users are allowed to perform soft reboots of server instances; it is recommended to disable soft reboots in policy (only allowing hard reboots) until the fix can be applied.

Credits

  • Tadayoshi Hosoya from NEC (CVE-2020-17376)

  • Lee Yarwood from Red Hat (CVE-2020-17376)

Notes

  • The stable/rocky, stable/queens, and stable/pike branches are under extended maintenance and will receive no new point releases, but patches for them are provided as a courtesy.