Firewall Rule Risk
Evaluate firewall rules for over-permissive exposure.
Last reviewed by the Radiatus Cloud team
Need this monitored 24/7?
Radiatus delivers managed cloud & network operations.
The rule that says "allow everything" is the one that bites
Firewall rulesets grow by accretion, and somewhere in them is usually a rule broader than anyone intended: a source of any, a destination of the whole internal range, a port range that was meant to be one port. This tool evaluates firewall rules for over-permissive exposure, flagging the ones that open more than they probably should.
What over-permissive looks like
The warning signs are specific: a source address of 0.0.0.0/0 on an inbound rule exposes a service to the entire internet; a wide destination range means one rule reaches many hosts; an any-port rule opens far more than a single service needs. Individually each may be deliberate, but flagged together they are a checklist of the places where least privilege has quietly slipped.
Least privilege, made reviewable
The value of surfacing broad rules is that it turns an unreadable ruleset into a short list of things to justify. For each flagged rule you either confirm the breadth is intended or tighten it, which is exactly the review that rarely happens because scanning a long ruleset by eye is so tedious. The evaluation runs in your browser, so your ruleset is not uploaded.
Related tools
- Port Scanner — Check which common ports respond on a host and understand what each exposed service means. Scan only systems you are authorised to test.
- DNS Misconfiguration — Analyze DNS records (TXT, SPF) for security gaps.
- TLS Compat Tester — Check client-server compatibility for TLS versions.
- Port Exposure Explainer — Understand risks of specific open ports.
Frequently Asked Questions
What makes a firewall rule over-permissive?
A source of any (0.0.0.0/0) on inbound traffic, a destination covering a wide range of hosts, or an any-port allowance, each of which opens more than a specific service needs.
Why does an any-source inbound rule matter?
Because it exposes the service to the entire internet rather than to known clients, which is the single most common cause of accidental exposure.
Does flagging a rule mean it is wrong?
Not necessarily. It means the rule is broad and worth justifying. Some broad rules are intentional; the point is to review them deliberately rather than let them hide in a long list.
What should I do with a flagged rule?
Either confirm the breadth is genuinely needed or tighten the source, destination or port to the minimum the service requires.
Is my ruleset uploaded?
No. The evaluation runs entirely in your browser.
Privacy & Security
Processed locally.
About This Tool
This tool runs entirely in your browser. No data is sent to any server, ensuring complete privacy. Simply use the interface above to get started — no registration or login required.
Disclaimer: This tool is provided "as is" without warranty of any kind. Results are for educational and utility purposes.
Related Tools
Port Scanner
NetworkCheck which common ports respond on a host and understand what each exposed service means. Scan only systems you are authorised to test.
DNS Misconfiguration
NetworkAnalyze DNS records (TXT, SPF) for security gaps.
TLS Compat Tester
NetworkCheck client-server compatibility for TLS versions.