Here’s the thing: VPNs are one of the most common ways companies connect remote employees and branch offices to their networks. But you know what’s funny? With all their importance, VPNs often get configured with the kind of sloppy shortcuts that could invite disaster. I’ve seen it time and again — over-permissive rules, default passwords, patch delays, you name it. And when VPNs screw up, it’s not just embarrassing; it’s ransomware, data leaks, and systems held hostage.
In this post, I’m going to give you a hard-hitting checklist to perform a lean, mean corporate VPN security audit. I’ll mention vendors like SonicWall, Ivanti, and Check Point Software — because yes, these big names still fall prey to classic configuration blunders. We’ll also touch on tools and concepts like Incogni and VPN penetration testing to give you a pragmatic edge. By the end, you’ll know exactly how to audit VPN security and spot the landmines before they blow up your network.
Why VPNs Are Both Your Best Friend and Worst Enemy
Virtual Private Networks, or VPNs, are often hailed as the standard solution to secure remote access. And no doubt — when properly configured and maintained, they add a crucial layer of encryption and control. But here’s the kicker: the danger mostly comes not from the technology itself, but from poor configuration.
Ever notice how IT folks sometimes treat VPNs like a “set it and forget it” appliance? You configure it once, push out connections, then move on to the next fire drill. That complacency sets the stage for over-permissive rules, outdated firmware, and default credentials — the perfect cocktail for an attacker to slip right in.
The Real-World Consequences of VPN Misconfigurations
Let me break down some scenarios I’ve seen firsthand:
- Ransomware campaigns: Attackers exploit VPN vulnerabilities or weak authentication to access internal systems, then deploy ransomware. You end up with entire departments locked out and a hefty ransom demand in Bitcoin. Data exfiltration: Credentials leaked or stolen from VPN endpoints can let attackers roam laterally across your network, siphoning intellectual property or PII. If you’re regulated, this is a compliance disaster waiting to happen. Service disruption: Misconfigured VPN tunnels can lead to network loops or doS (Denial of Service) conditions, causing downtime that halts operations. Insider risk magnified: Without strict segmentation, a rogue or compromised user with VPN access can do more damage than you think, moving laterally like a ghost.
So what’s the takeaway here? VPNs are a double-edged sword — incredible when dialed in, catastrophic when left to fester.
Common Mistakes in VPN Configuration to Watch Out For
Let me call out some of the usual suspects that I find in VPN security audits regularly:
Over-permissive firewall and access rules: You get administrators who simply allow “any any” or similarly loose rules on VPN policies just to avoid fuss. That means, potentially, every user connected via VPN can reach every internal system — a hacker’s playground. Using default credentials on appliances: This is fundamental but still happens. Folks forget to change admin passwords on gateways or VPN concentrators like those from SonicWall or Check Point. It’s like leaving your front door unlocked in a bad neighborhood. Failing to patch VPN infrastructure: Vendors like Ivanti and SonicWall regularly release critical updates to patch vulnerabilities. Those patches need to happen — yesterday. Ignoring multi-factor authentication (MFA): Relying solely on username and password is asking for trouble. MFA should be a baseline requirement for VPN access. Lack of proper segmentation: Treating VPN connections as a “flat” network where everyone sees everything is a recipe for disaster. Neglecting log monitoring and alerting: If you’re not watching VPN logs for unusual activity, you’re flying blind.How to Audit VPN Security: Your No-Nonsense Checklist
Alright, let’s cut to the chase. Grab a strong black coffee and your favorite VPN dashboard — whether it’s Ivanti, SonicWall, Check Point Software, or any other vendor — and walk through these steps.
1. Inventory Your VPN Assets and Usage
- Catalog all VPN devices, concentrators, and endpoints. Who’s got remote access? What apps do they reach? Check versions and patch statuses of VPN appliances and clients. Identify unused or obsolete VPN tunnels that just add risk with no benefit.
2. Review VPN Configuration Settings
- Look for default or weak credentials, including hidden defaults in management interfaces. Validate encryption algorithms and protocols used—no PPTP or weak 3DES. Prefer strong options like IKEv2, AES-256. Verify VPN timeout and session disconnect policies. Prevent long idle sessions that keep doors open unnecessarily.
3. Audit Access Control and Firewall Rules
This is where you drill into over-permissive rules. Consider this example:
Rule Source Destination Protocol Action Comments 1 VPN subnet Internal network Any Allow Over-permissive — too broad- Identify any “allow all” or overly broad rules. Pinpoint rules that don’t respect least privilege principles. Test segmentation by simulating user access (hint: use VPN penetration testing tools and techniques).
4. Confirm Multi-Factor Authentication Is Enforced
- Check whether MFA is enabled for every VPN user. Review MFA methods used — hardware tokens, TOTP apps, or other options. Test fallback mechanisms to ensure they don’t weaken security.
5. Examine Logging and Monitoring Practices
- Verify that VPN connections are logged with sufficient detail. Confirm that alerts exist for anomalies such as repeated login failures or concurrent sessions. Use threat intelligence feeds (you can integrate tools like Incogni to monitor data leaks tied to VPN credentials).
6. Conduct VPN Penetration Testing
Nothing beats a real-world simulation. Use VPN penetration testing to probe for:
- Authentication weaknesses Misconfigured tunnels Vulnerabilities in VPN appliances — especially those with recent CVEs Brute force or credential stuffing attacks
Make sure this is done by skilled testers (internal or third-party) who know your environment and toolsets.
Balancing Security and Usability: The Real Challenge
You face a classic conflict: tighten VPN security and users complain about complexity or connectivity issues; loosen it, and risk open doors for attackers. Here’s the reality:
- There is no security without usability. If your team can’t connect, they’ll find shadow methods to get work done — think unsecured personal VPNs or file shares. Conversely, user complaints about MFA or strict timeout policies are a small price to pay compared to the fallout from a breach. Make sure your audit recommendations address both sides, and coordinate changes with user training and support.
Why You Can’t Trust Default Settings on Network Appliances
Seriously, if I had a dime for every time I found a SonicWall or Check Point VPN device ship with admin passwords still set to factory defaults — I wouldn’t need my garage full of old firewalls. Default settings are convenience for your vendor, a liability for your company.
Here are common default setting pitfalls:
- Default SNMP community strings that leak info Default admin passwords that attackers can easily guess or brute force Default open ports or services that expand attack surface Default logging disabled or set too low — no visibility
Changing defaults in your VPN infrastructure is not optional. It’s your first line of defense.
Wrapping Up: Make Your VPN Audit a Repeating Ritual
Let’s be real — security audits aren’t one-and-done checkboxes. VPNs evolve with your company’s needs; Go here users come and go; threats get smarter. Make VPN security auditing a scheduled, repeatable discipline. Incorporate vulnerability scanning and penetration testing regularly. Utilize tools like Incogni to feed threat intel into your processes.
And when you’re reviewing those configurations, keep the checklist I laid out here handy:
Inventory assets and usage Review VPN setup and cryptography Audit and tighten access rules Enforce multi-factor authentication Implement detailed logging and monitoring Conduct VPN penetration testingWith this approach, you’ll not only know how to audit VPN security comprehensively but also avoid the pitfall of “setting it and forgetting it.” Because trust me, when it comes to VPNs, your adversaries absolutely won’t.
Written by a seasoned network security analyst whose garage tells the tale of too many misconfigured firewalls.