Telnet management enabled
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
Telnet sends the administrator's credentials and session in clear.
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.
- In ASDM: Configuration > Device Management > Management Access > ASDM/HTTPS/Telnet/SSH, delete every Telnet entry and use SSH. Apply and save.
- On the CLI: clear configure telnet, and write memory.
Command line
Cisco ASA CLI
configure terminalclear configure telnetendwrite 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 telnetBefore 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>).
- Confirm your own session is not using the service you are turning off.
How to confirm the fix
- Run show running-config telnet and confirm nothing remains.
Limits
- No limitation is recorded for this control beyond the one that applies to all of them: it reads a configuration export.
Compliance references
CIS Cisco ASA 9.x Firewall Benchmark v1.1.0
Covers the whole recommendation
Where a control aligns with a recommendation of the CIS Cisco ASA 9.x Firewall Benchmark v1.1.0, that recommendation is cited as a reference. Only that version was checked. A reference is not a certification.
More in Administrators and Access
- ASA-SEC-016ICMP to the device allowed from any address on an untrusted interface
- ASA-MGT-001ASDM and HTTPS management exposed
- ASA-MGT-002SSH management exposed
- ASA-MGT-004Management on a data interface
- ASA-MGT-005SSH version 1 allowed
- ASA-MGT-006Weak TLS for management and SSL VPN
- ASA-MGT-007SSH key exchange with SHA-1
- ASA-MGT-008Console timeout too long
See it on your own firewall
One complete analysis of one firewall costs nothing. A card is required and nothing is charged.