07 — The Dangers of Not Restricting Remote Firewall Access
Lunch Revisions So Real (Post The Third Cup Of Coffee On My Desk)
Data Maximum Up is Tolerance with CyberSecurity, Below.
I was a lowly network admin in the ’93 dinosaurs-roamed-the-earth, multiplexers-make-the-world-go-round days of corporate life. It’s not glamorous, but managing voice and data over PSTN is where I learned a lot about the backbones of security… and failure. Then in 2003 there was the Slammer worm, ripping through networks like a hungry predator. I won’t forget those frantic days — firewalls not sufficiently locked down, remote admin ports left wide open like a barn door.
Fast forward to today: running P J Networks, working with banks to enhance their zero-trust setups, and still buzzing fresh from this year’s DefCon hardware hacking village. If you believe that firewall management is an archaic artifact, think again. Here’s the deal: unprotected remote firewall access is a ticking time bomb and if you’re not paying attention, it’s like sending hackers an invitation to tea.
Let’s dig into why this is a big deal, and what more importantly, why this is what you need to do about it.
Risks of Unsecured Access
Think of your firewall as the guardian of your home — but rather than a solid, locked door, you have a flimsy screen door swinging open on a windy day. Unrestricted remote firewall access is this open door.
Here’s what your poorly configured remote access can invite:
- Unauthorized intrusions. Know that hackers are scanning public IPs for admin ports (i.e. 80, 443, 8080, or goodness gracious, non-custom low ports left open). It’s like giving someone your master key.
- Worms and malware, automated. Remember Slammer? Intel’s still traumatized by that worm’s rapidity — unrestricted remote access means worms and bots can penetrate without warning.
- Brute force and credential stuffing assaults. If your firewall access doesn’t have a limit to the number of attempts for logging in, or a lockout mechanism for repeated failures, attackers will keep continuing to match your passwords until they succeed.
- Use of zero-day vulnerabilities. Remote consoles with known or previously unknown bugs can be abused without anyone noticing until it is too late.
- Lateral movement within your network. Once inside the management interface of your firewall, an attacker can pivot into other key systems, rendering your fortress to be more like Swiss cheese.
Believe me, I found out the hard way dealing with banks recently. 05: One client exposed remote firewall admin without a proper password and without multi-factor. Checking the logs revealed that at odd hours there were multiple failed log-in attempts from overseas IPs. They were this close to a total breach.
For More Information on Remote Admin Best Practices
Ok, so now that we are all on the same page that opening remote admin access is like leaving the door of your car unlocked in a seedy neighborhood, what do you actually do?
Here’s a succinct check-list to fortify that wall around your firewall:
- Whitelist trusted IPs ONLY.
E.g.: Limit remote management access to known VPN IPs or static office locations. No exceptions. - Admin Interface Is Not on Standard Ports
While changing default ports will not deter a dedicated attacker, this makes the attack easier for opportunistic scans. - Keep up-to-date about the firmware and any patch vulnerabilities—even without excuses, out-of-date firewalls are the open door. If it’s not woven or maintained, it becomes a liability.
- Log checking should be done vigilantly and alerts need to be automated for suspicious activity.
- Grant only the most minimal level of privileges administratively. Not all tech requires the keys to kingdom.
And here is something that I say at every client site, even if it makes me sound old-fashioned: never trust a password policy. You can have a password that’s a 25-character monster, but if you leave the door unlocked, that doesn’t matter.
Implementing MFA
MFA should be the absolute bare minimum.
Here’s the dirty little secret about passwords: They’re terrible at stopping anything of value from getting stolen. Over the years, I’ve seen every bad password policy you can imagine. Rules such as: Change your password every 30 days! just result in pious platitudes and sticky notes on the edge of the monitors.
MFA introduces a second line of defense — something you know (password) and something you have (push notification, hardware token or even a biometric check). MFA-less remote access to your firewall is like balling out on a secure vault but giving the combination to anyone who asks for it politely.
Most recently, I’ve assisted three banks with enforcing MFA on their firewall management portals. The results are on the table: zero unauthorized admin access incidents since rollout. Period.
Some people tout AI-powered authentication as the panacea — but can I tell you something? AI is mostly marketing sparkle. MFA Is Easy, With Impact, and Resilient. Focus on that first.
VPN-Based Access
Remote firewall access must always go through a strong VPN tunnel.
Why VPN? Two reasons:
- It encrypts your management traffic from end to end.
- It allows only your trusted authenticated remote users to access.
I’ve encountered an organization expose their firewall admin port directly to the internet—yikes! They effectively ignored the VPN saying, The password on our firewall is strong. Wrong mindset. Without VPN, you’re exposing your admin interface in plain text anyone with an IP scanner.
A couple of tips:
- Use VPNs using strong encryption (OpenVPN, WireGuard (avoid weak, deprecated protocols).
- Enforce session timeouts and require re-authentication for sensitive admin tasks.
- If you combine your VPN access with IP whitelisting policies, you will then have double doors instead of just one.
Disabling Unused Ports
Sounds obvious—but frequently ignored. Firewalls and routers ship with a full suite of management ports: SSH, Telnet, HTTP, HTTPS, SNMP, etc. You won’t use half of them.
My no-nonsense advice: turn off everything you don’t need.
- If you aren’t using Telnet — disable it.
- SNMP with no authentication enabled? Kill it.
- Administration over HTTP not HTTPS? Please, no.
The less exposed your device, the fewer attack surfaces hackers are able to scan and use.
Quick Take: The Bottom Line
- Open remote firewall access is like candy for hackers—don’t hand them around.
- IP whitelisting, update and patch like a religion, restrict administrative access.
- Enforce MFA. No excuses.
- Require VPN for remote admin access.
- Turn off all unnecessary and insecure ports on your firewall.
Conclusion And Possibly A Rant
I can’t tell you how many times in my career I’ve seen companies “go fast” with their remote access setup only to go much slower when they got hacked.
The bottom line: Cybersecurity is not a sprint, it’s a marathon. You’re not going to race a Ferrari with a flat tire, yet they are running their networks wide open and expecting a miracle.
At P J Networks Pvt Ltd, we have a passion for firewall and remote access security, and we wake up every day to live and breathe it. If you’re dealing with critical infrastructure like those banks I helped or your own business, remote firewall access locking is not optional, it’s mandatory.
And yes, I’m still astounded that some organizations trust AI black boxes before shoring up basic MFA and VPN hygiene. Old school? Maybe. Effective? Absolutely.
Now, off to make my fourth cup of coffee. Until next time — keep those gates locked and watch those logs.
Sanjay Seth
Founder & Cybersecurity Expert
P J Networks Pvt Ltd
All from multiplexers to malware, and now zero-trust — we’ve seen all. Let’s take care of your future today.