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ConfigProof

All controls

ASA-MGT-017MediumCisco ASA

NTP not authenticated

At a glance

Base severity

Medium

Area

System and Metadata

Platform

Cisco ASA

Evidence level

Fact1.00

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

An unauthenticated time source can be spoofed, which corrupts log timestamps and certificate validity checks.

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.

  1. In ASDM: Configuration > Device Setup > System Time > NTP, edit each server with a Key Number, check Trusted and Enable NTP authentication. Apply and save.
  2. On the CLI: ntp authentication-key 1 sha256 <key>, ntp trusted-key 1, ntp authenticate, ntp server <server> key 1, and write memory.

Command line

Cisco ASA CLI

configure terminalntp authentication-key 1 sha256 <key>ntp trusted-key 1ntp authenticatentp server <ntp-server> key 1endwrite 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 ntp associations detail
Values to fill in2
<key>
A new shared key
<ntp-server>
An NTP server's address
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>).
  • In multiple context mode, failover, clustering and resource classes are configured in the system execution space.

How to confirm the fix

  • Run show ntp associations detail and confirm authenticated.

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.

More in System and Metadata

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