What evidence do auditors commonly ask for on 26 Software firewall - outbound (Very Good)?

Egress test results from a sample workstation showing an unapproved executable unable to open outbound connections; Outbound host firewall rules allowing network traffic only from approved programs, with the approval list; Change records for adding programs to the outbound allow list; Logs of blocked outbound connection attempts from unapproved processes.

What is the most common gap auditors find on 26?

Outbound traffic allowed from any process by default, so malware can call home freely

ASD Strategies to Mitigate Cyber Security Incidents · Limiting the Extent of Cyber Security Incidents

`26` Software firewall - outbound (Very Good)

Software-based application firewall, blocking outgoing network traffic that is not generated by approved/legitimate programs.

Source: ASD Strategies to Mitigate Cyber Security Incidents, 26. The statement above is our statement of the clause, read from the published text and cited so you can check it against the official text, not the instrument verbatim. Open ASD Strategies to Mitigate Cyber Security Incidents in the compliance library.

artefacts

held by a system

at each review

easy

to go live

Cloud console / configuration management

where the evidence lives

teal = a system already holds it · olive = produced at each review. To go live: easy when half or more of the artefacts are already held by a system, moderate from a quarter to a half, hard below a quarter.

These are the artefacts auditors commonly ask for on this requirement, our guidance rather than text from the standard. Your assessor decides what is sufficient in your context, and asks for samples across the period when a report covers one.

system holds itEvidence a system already holds

Outbound host firewall rules allowing network traffic only from approved programs, with the approval list · Cloud console / configuration management
Change records for adding programs to the outbound allow list · Document repository
Logs of blocked outbound connection attempts from unapproved processes · SIEM / log platform

periodic reviewEvidence produced at each review

Egress test results from a sample workstation showing an unapproved executable unable to open outbound connections · Endpoint management (MDM / EDR)

governing documentDocuments that govern the control

none for this control

First move

Automate the pull from your Cloud console / configuration management. Configuration snapshots and change history from the cloud console or IaC repository, diffed against the baseline.

Common gaps auditors find

Outbound traffic allowed from any process by default, so malware can call home freely
Allow list keyed on generic interpreters such as PowerShell or browsers, undermining the restriction
Blocked outbound events never reviewed as possible signs of compromise

Do this for your whole sheet

Paste the rows you run your controls from and get this mapping for every control at once, with the periodic-review ones flagged and a first move per row. No account for the first run.

Build my evidence sheet

25 Software firewall - inbound (Very Good) · 27 Outbound data loss prevention (Very Good)