EC2 Source/Destination check is off
- Severity
- Info
- Service
- EC2
- Check ID
- EC2_SOURCE_DEST_CHECK_OFF
What this check finds
If there are no routes, this is not doing anything and the Source/Destination check should be re-enabled.
Passing looks like: EC2 source/destination check enabled.
How to fix it
Re-enable Source/Destination check unless this EC2 is explicitly acting as a NAT instance or network appliance.
AWS CLI
aws ec2 modify-instance-attribute --instance-id INSTANCE_ID --source-dest-check '{"Value": true}'
Names in capitals are placeholders for your own resource. Review a command before you run it.
AWS console
EC2 → Instances → select instance → Actions → Networking → Change source/destination check.
Compliance controls it is evidence for
A failing result counts against these controls in KloudLytics; a passing one is evidence towards them. How compliance mapping works
| Framework | Controls |
|---|---|
| NIST SP 800-53 Rev5 (Moderate) |
|
| NIST Cybersecurity Framework 2.0 |
|
| ISO/IEC 27001:2022 Annex A |
|
Checked on every scan
KloudLytics runs this check each time it scans a connected AWS account, through a read-only role, and lists every affected resource with its region. On Pro and Business a fix is written for the specific resource rather than the general case above. The exact access it needs
More EC2 checks
- HighAccount does not block public sharing of EBS snapshots
- HighAMI is publicly shared
- HighEBS snapshot is public
- HighEC2 instance CPU spiked abnormally — possible compromise or runaway process
- HighEC2 instance has an IAM role with admin privileges
- MediumAccount default for instance metadata does not require IMDSv2
- MediumEBS default encryption is not enabled for this region
- MediumEBS volume is not encrypted at rest