Access list entry with no hit in 90 days of readings
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
An entry no traffic has matched over a long window is probably obsolete, and an obsolete permit entry widens what the firewall admits.
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.
- Ask the entry's owner whether it is still needed. If not, make it inactive first, watch for a business cycle, then remove it and write memory.
Command line
Cisco ASA CLI
configure terminalaccess-list <access-list> line <line> <entry> inactiveendwrite 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 access-list <access-list>Values to fill in3
- <access-list>
- The access list
- <line>
- The entry's line number in the list
- <entry>
- The entry's text after the line number, as the device shows it
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>).
- A configuration shows definitions and references, not traffic, so review this before you run it.
How to confirm the fix
- On the ASA (read only): show access-list <list>, and confirm the entry's hitcnt does not move between two reads.
Limits
- An entry kept for a rare event (disaster recovery, a yearly job) can show no hit and still be needed.
- A counter cleared and counted back to the same value between two readings is not seen.
Compliance references
No benchmark recommendation is mapped to this control in this version.
More in Security Policies
- ASA-SEC-001Inbound entry allows any destination or any service
- ASA-SEC-002permit ip any any entry
- ASA-SEC-004Untrusted inbound list without an explicit logged deny
- ASA-SEC-005Entry another entry already covers
- ASA-SEC-006Inactive entry left in a list
- ASA-SEC-009Remote administration, file sharing or database port open inbound
- ASA-SEC-022EtherType list permits any EtherType
See it on your own firewall
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