A flaw was found in the QEMU virtio-fs shared file system daemon (virtiofsd) implementation. This flaw is strictly related to CVE-2018-13405. A local guest user can create files in the directories shared by virtio-fs with unintended group ownership in a scenario where a directory is SGID to a certain group and is writable by a user who is not a member of the group. This could allow a malicious unprivileged user inside the guest to gain access to resources accessible to the root group, potentially escalating their privileges within the guest. A malicious local user in the host might also leverage this unexpected executable file created by the guest to escalate their privileges on the host system.

References

• https://nvd.nist.gov/vuln/detail/CVE-2022-0358
• https://access.redhat.com/security/cve/CVE-2022-0358
• https://bugzilla.redhat.com/show_bug.cgi?id=2044863
• https://gitlab.com/qemu-project/qemu/-/commit/449e8171f96a6a944d1f3b7d3627ae059eae21ca
• https://security.netapp.com/advisory/ntap-20221007-0008/