vulnerability / NVI-00018586 / Revision 1
Kata guest escape: runtime-rs guest-root to host-root escape via virtiofs
GitHub lists this reviewed advisory for github.com/kata-containers/kata-containers. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
github.com/kata-containers/kata-containers
source listed< 0.0.0-20260519062212-ffa59ce3aa78
### Summary In the runtime-rs standalone virtio-fs path, verified here with QEMU (and verified with Cloud Hypervisor too), Kata Containers runs host `virtiofsd` as root with: ``` --sandbox none --seccomp none ``` If an attacker has root-equivalent execution inside the Kata guest VM, they can send raw FUSE requests directly to the host `virtiofsd`. With the tested runtime-rs virtio-fs configuration, a raw `FUSE_SYMLINK` request whose new symlink name is an absolute host path is honored outside the virtio-fs shared directory. This lets guest root create host-root owned symlinks in sensitive host paths. The PoC created here will create symlinks in the host `/etc/cron.d` directory, causing host cron to execute a guest-controlled payload as host root. Impact: guest root can execute code as host root. ### Affected configuration The verified host used: ``` /opt/kata/share/defaults/kata-containers/runtime-rs/configuration-qemu-runtime-rs.toml rootless = false shared_fs = "virtio-fs" virtio_fs_daemon = "/opt/kata/libexec/virtiofsd" hypervisor_name = "qemu" debug_console_enabled = false ``` Pinned upstream references, using Kata Containers `main` commit `2ffd1538a296cff93a357bfba0d
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-2gv2-cffp-j227 ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.