CVE-2018-9853
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedInsecure access control in freeSSHd version 1.3.1 allows attackers to obtain the privileges of the freesshd.exe process by leveraging the ability to login to an unprivileged account on the server.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidencefreeSSHd 1.3.1 contains an insecure access control vulnerability that allows authenticated users with unprivileged SSH accounts to escalate their privileges to those of the freesshd.exe process, likely due to improper privilege handling or misconfiguration in how the service executes user sessions.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data= 1.3.1CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check if freeSSHd is installedOpen Control Panel > Programs and Features, or look for freesshd.exe in common installation directories such as C:\Program Files\freeSSHd or C:\freeSSHd. Alternatively, open Services (services.msc) and look for a service named 'freeSSHd' or similar.Affected if freeSSHd software is found on the system
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Verify the installed version is 1.3.1Right-click on freesshd.exe, select Properties, then go to the Details tab and check the Product Version field. Or run 'wmic product get name,version' if available.Affected if The version is exactly 1.3.1
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Confirm the SSH service is runningOpen Services (services.msc), find the freeSSHd service, and verify the Status shows 'Running'. Alternatively, run 'sc query freesshd' from an elevated command prompt.Affected if The freeSSHd service is installed and running
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Check for configured SSH user accountsOpen the freeSSHd configuration UI (freeSSHd.exe), go to the Users or SSH tab, and list all configured users. Each entry shows a username and associated shell/command.Affected if At least one unprivileged user account is configured with limited shell access (not Administrator)
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Identify the service account contextIn Services (services.msc), right-click the freeSSHd service, select Properties, and check the 'Log On As' field. This shows which account the service runs under.Affected if The service runs under an account with elevated privileges (such as LocalSystem, a domain admin, or a user with significant system access) while unprivileged SSH users exist
A user is affected if freeSSHd version 1.3.1 is installed with its SSH service running and at least one unprivileged user account is configured, allowing that user to potentially escalate privileges to the service account level.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataUpgrade freeSSHd to a patched version if available; otherwise migrate to a maintained SSH server implementation (such as OpenSSH for Windows) and review/adjust service account privileges.
- Consultation2.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,560.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-9853 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2018-9853 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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