CVE-2021-39291
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 · uneditedCertain NetModule devices allow credentials via GET parameters to CLI-PHP. These models with firmware before 4.3.0.113, 4.4.0.111, and 4.5.0.105 are affected: NB800, NB1600, NB1601, NB1800, NB1810, NB2700, NB2710, NB2800, NB2810, NB3700, NB3701, NB3710, NB3711, NB3720, and NB3800.
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 analysisSensitive values — secrets, tokens, session identifiers, personal data — are written into log files, so anyone with access to the logs, which is often a broad group, obtains them. It turns a routine diagnostic into a credential leak. The fix is redacting sensitive data before it is logged and tightly restricting who can read the logs.
General guidance for the sensitive information in logs class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →
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< 4.3.0.113>= 4.4.0.0, < 4.4.0.111>= 4.5.0.0, < 4.5.0.105CVSS 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
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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.
dbcve · scoped4.3.0.1134.4.0.1114.5.0.105
NetModule Router Software 4.3.0.113, 4.4.0.111, or 4.5.0.105 (or later) depending on firmware branch
- 1. Identify the current NetModule router model (NB800, NB1600, NB1601, NB1800, NB1810, NB2700, NB2710, NB2800, NB2810, NB3700, NB3701, NB3710, NB3711, NB3720, or NB3800) and its current firmware version via the device web interface or CLI.
- 2. Determine which firmware branch the device is running (4.3.x, 4.4.x, or 4.5.x).
- 3. Download the appropriate fixed firmware version from the official NetModule support portal: upgrade to 4.3.0.113 or later for 4.3.x branch, 4.4.0.111 or later for 4.4.x branch, or 4.5.0.105 or later for 4.5.x branch.
- 4. Review NetModule firmware upgrade documentation for your specific model.
- 5. Back up the current device configuration.
- 6. Upload and apply the new firmware via the web interface or CLI, following vendor instructions.
- 7. After reboot, verify the firmware version has been updated successfully.
- 8. Confirm the vulnerability is remediated by testing that credentials are no longer logged in system logs when accessing CLI-PHP.
Generated from the published advisory — verify against the referenced sources before acting.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-39291 — 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-2021-39291 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
- No spam, self-promotion, credentials, or personal data