VPN tunnel configured for IKEv1 only
At a glance
Base severity
Area
Platform
Evidence level
Benchmark reference
Reads the export, not the device
ConfigProof reads a configuration export. This control is evaluated against the objects in that file, and it reports what the file says. It does not connect to the device and sees no traffic, so a finding here describes the configuration, not what the firewall is doing right now.
Why it matters
IKEv1 lacks the protections IKEv2 adds against denial of service and downgrade, and ASA 9.20 removed IKEv1 IPsec over TCP.
How to fix it
Web interface
The steps below are written for the web interface. A finding raised on your own export carries the same steps with your object names filled in.
- Enable IKEv2 on the interface with crypto ikev2 enable <nameif>, and define a crypto ikev2 policy.
- Under the peer's tunnel-group ipsec-attributes, set ikev2 local-authentication and remote-authentication, and on the crypto map entry or IPsec profile set ikev2 ipsec-proposal.
- Move the peer at a time agreed with its owner, then remove the ikev1 lines.
Command line
Cisco ASA CLI
configure terminalcrypto ikev2 enable <nameif>tunnel-group <peer> ipsec-attributesikev2 local-authentication certificate <trustpoint>ikev2 remote-authentication certificateexitcrypto map <crypto-map> <sequence> set ikev2 ipsec-proposal <ipsec-proposal>endwrite memory
An example. Values in angle brackets are yours to supply; a finding on your own export fills in the names it read. Typed in configuration mode; write memory saves it, with no separate commit. Read every line first.
Read it back
show running-config tunnel-group <peer>show crypto ikev2 sa
Values to fill in6
- <nameif>
- The interface name (nameif)
- <peer>
- The peer
- <trustpoint>
- The trustpoint holding the identity certificate
- <crypto-map>
- The crypto map
- <sequence>
- The crypto map entry's sequence number
- <ipsec-proposal>
- A name for the new IPsec proposal
Before you type it3
- Written from the ASA 9.x command reference and not run on a device: read each line before you paste it.
- In multiple context mode, type it in the context it applies to (changeto context <name>).
- The far end has to offer the same proposal, so coordinate the change with whoever runs it.
How to confirm the fix
- Run show running-config crypto map and show running-config tunnel-group <peer> ipsec-attributes, and confirm the IKEv2 settings.
Limits
- No limitation is recorded for this control beyond the one that applies to all of them: it reads a configuration export.
Compliance references
No benchmark recommendation is mapped to this control in this version.
Weak cryptography and protocols
- CRY-VPN-001IKEv1 where IKEv2 is possible
See it on your own firewall
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