CVE-2023-3336
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 · uneditedTN-5900 Series version 3.3 and prior versions is vulnearble to user enumeration vulnerability. The vulnerability may allow a remote attacker to determine whether a user is valid during password recovery through the web login page and enable a brute force attack with valid users.
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 · high confidenceThe TN-5900 Series web login page's password recovery function reveals whether specific usernames are valid by returning different responses for valid versus invalid users. This information disclosure allows remote attackers to enumerate valid user accounts, which then enables targeted brute force attacks against those confirmed accounts.
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<= 3.3CVSS 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
- Low
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
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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Confirm Moxa TN-5900 Series deviceIdentify your device model through the device label, web interface, or SNMP inventory. This vulnerability only affects TN-5900 Series hardware.Affected if Device is not a Moxa TN-5900 Series model
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Check installed firmware versionAccess the device web interface and navigate to System > Firmware Version, or use the command line and run 'show system info' or check the firmware file loaded on the device.Affected if Firmware version is 3.3 or lower
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Verify web interface is enabledCheck device network settings via console or administration interface to confirm the web server (HTTP/HTTPS) is enabled and accessible on the network.Affected if Web interface is enabled and network-accessible (required for exploitation)
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Determine if password recovery is exposedAccess the device login page and locate the password recovery or 'forgot password' function. Confirm it accepts a username or email as input.Affected if Password recovery feature is accessible on the web interface
Your environment is affected if you have a Moxa TN-5900 device running firmware version 3.3 or lower with the web interface enabled, as the password recovery function can be queried to enumerate valid usernames.
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 dataImplement uniform error responses for password recovery regardless of whether the submitted username or email exists, preventing user enumeration. Additionally, consider implementing account lockout policies and rate limiting on authentication endpoints.
- Consultation1.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-3336 — 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-2023-3336 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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- 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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