A network security audit rarely turns up something exotic – it turns up the same handful of issues, server after server, quarter after quarter. If you’ve just received a port security audit findings report and you’re staring at forty line items wondering which ones actually matter, this breaks down what shows up most often, why it happens, and what to fix first.
Most findings fall into five or six recurring categories. Auditors see them across e-commerce platforms, SaaS backends, and on-prem file servers alike, because the root causes are organizational, not technical – default configs never revisited, decommissioned test boxes left running, and firewall rules that outlived the project they were written for.
Exposed management interfaces on default ports
RDP on 3389, SSH on 22, and database admin panels reachable from 0.0.0.0/0 make up a large share of every audit report. A Windows box left with RDP open to the internet is still one of the fastest paths to compromise – BlueKeep (CVE-2019-0708) proved that in 2019, and unpatched RDP servers are still being scanned and exploited in 2026.
The pattern is almost always the same: a developer opened the port for a one-time task, a temporary firewall rule was never rolled back, and six months later nobody remembers why it’s there. An experienced auditor doesn’t just flag the open port – they check whether it’s reachable from the whole internet or scoped to a VPN range, since that distinction changes the finding from critical to low.
Legacy protocols still listening
FTP (21) and Telnet (23) keep appearing in audits of infrastructure that’s otherwise modern. They’re usually leftovers from a legacy integration – a vendor’s firmware update tool, an old backup script, a printer that shipped with Telnet enabled by default. Both protocols transmit credentials in plaintext, so any finding here gets flagged regardless of how “internal” the box feels.
Database ports reachable without authentication context
MongoDB on 27017, Redis on 6379, and Elasticsearch on 9200 show up constantly, usually because the service was deployed with its out-of-the-box configuration and never bound to a private interface. Redis in particular ships with no authentication by default in many versions prior to 6.0, which means an open 6379 is effectively an open database. This is the single most common root cause behind the ransomware waves that hit exposed MongoDB and Elasticsearch clusters between 2017 and 2020, and the same misconfiguration pattern is still being found in fresh cloud deployments today.
Outdated service versions behind open ports
An open port by itself is a risk signal; an open port running an unpatched service version is a confirmed vulnerability. Audits regularly turn up Apache 2.4.49 (CVE-2021-41773), old OpenSSH builds, or EOL versions of nginx still answering on port 443. Version detection during a scan is what separates “port 443 is open” from “port 443 is running a build with a known path traversal bug” – the second one needs a patch ticket opened same day, not next sprint.
Cloud security group misconfigurations
In AWS, Azure, and GCP environments, a large share of findings trace back to security groups or NSGs left wide open during initial setup and never tightened. A rule allowing All Traffic from Anywhere on an EC2 instance is common enough that most cloud-focused audits treat it as an expected finding rather than an anomaly – which says more about deployment habits than about the platforms themselves.
Decommissioned servers still answering
Old staging servers, retired VMs that never got fully powered off, and orphaned load balancer targets routinely turn up during external scans months or years after the team assumed they were gone. These are some of the most dangerous findings precisely because nobody is watching them – no monitoring, no patching, no owner. See how to decommission old servers without leaving ports open for the checklist most teams skip.
What auditors get wrong when triaging findings
Three mistakes come up repeatedly in how teams handle audit results. First, treating every open port as equally urgent, which buries the RDP exposure under forty low-risk findings about closed-but-filtered ports. Second, closing the port without investigating why it was open in the first place – if a firewall rule gets reverted a week later by an automation script nobody audited, the finding just comes back. Third, trusting a single scan snapshot instead of tracking findings over time; a port that was closed during last quarter’s audit but reopened by a deployment script in between scans is a much bigger problem than one that’s been open continuously and known about.
A common misconception worth correcting
A lot of teams assume that if a port isn’t in the official documentation or the asset inventory, it doesn’t exist as a risk. External scanning doesn’t care about your inventory – it finds what’s actually listening, not what’s supposed to be listening. The gap between “what we think is running” and “what’s actually reachable” is exactly what most audit findings represent, and closing that gap requires understanding the difference between open, closed, and filtered port states rather than assuming a clean asset list means a clean attack surface.
Turning findings into a remediation plan
Once the report is in hand, the order of operations matters more than the number of findings. Start with anything exposing authentication-free services or known-exploited CVEs, move to unnecessary management interfaces reachable from the public internet, then work through legacy protocols and stale rules. Prioritizing findings by risk level keeps a 60-item report from turning into a 60-item backlog nobody finishes.
FAQ
How many findings is normal for a first-time port security audit?
Environments that have never been scanned externally commonly return 15–40 findings on a mid-sized infrastructure of 10–30 servers, most of them low or informational severity rather than critical. A near-zero result on a first audit is unusual enough to double-check scan coverage before assuming the environment is clean.
Do closed or filtered ports still count as findings?
Usually not as security findings, but they’re worth noting for baseline comparison. A port that shows filtered today and open next month is a change worth investigating even if neither state was flagged as critical.
Should every open port be closed?
No – plenty of open ports are legitimate, like 443 for a public web app. The finding isn’t “port open,” it’s “port open with no business justification, weak authentication, or a known vulnerable version behind it.” Common port misconfigurations that lead to breaches covers how to tell the difference.
Most audit reports look overwhelming until they’re sorted by exposure and exploitability. Start with anything reachable from the open internet with no authentication in front of it, work outward from there, and re-scan on a schedule tight enough to catch the next stale firewall rule before an attacker does.