ENCLAVE-03: Multi-enclave co-tenancy¶
| Property | Value |
|---|---|
| Severity | medium |
| Platform | AWS Nitro Enclaves |
| Lifecycle stage | runtime |
| Mode | Active: runs fixed read-only commands on the host. Skipped with --read-only. |
What it checks¶
It passes when:
- … enclave running. No co-tenancy risk.
Example failures:
- … enclaves running on the same host: …. Shared hugepage pool and CPU contention create side-channel and resource starvation risks.
- 2 enclaves running on the same host: i-0abc123-enc-0001, i-0abc123-enc-0002. Shared hugepage pool and CPU contention create side-channel and resource starvation risks.
How to fix¶
- Run exactly one enclave per host. Separate workloads onto dedicated EC2 instances to eliminate resource contention and co-tenancy side-channels.
After the fix, scan again: the check should report PASS.
When it is not assessed¶
SKIP:
- No instance ID specified; skipping check.
ERROR:
- SSM command did not complete within timeout.
- nitro-cli not available or no enclaves found.
- Could not send SSM command: …
- Could not parse nitro-cli output.
Scan inputs¶
The untrust scan options this check reads:
| Option | Description |
|---|---|
--instance-id |
EC2 instance ID running the Nitro Enclave. |
--region |
AWS region. |
Permissions¶
The cloud API calls this check makes, read from the scanner's source:
| Cloud | API call | Permission | Access |
|---|---|---|---|
| AWS | ssm.get_command_invocation |
ssm:GetCommandInvocation |
read |
| AWS | ssm.send_command |
ssm:SendCommand |
run command |
Every AWS scan also calls sts:GetCallerIdentity. See Required permissions for a complete policy.
Evidence recorded¶
Keys in the finding's evidence: running_enclaves, total_count
Generated from untrust 1.3.0 (commit 7ef462d9a0c3).