CVE-2021-27372
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 · uneditedRealtek xPON RTL9601D SDK 1.9 stores passwords in plaintext which may allow attackers to possibly gain access to the device with root permissions via the build-in network monitoring tool and execute arbitrary commands.
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 Realtek xPON RTL9601D SDK version 1.9 stores user and potentially administrator passwords in plaintext rather than using secure hashing. Attackers with access to the device can retrieve these plaintext passwords via the built-in network monitoring tool, which grants root-level access and enables arbitrary command execution.
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= 1.9CVSS 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:3.1/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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Identify device and SDK versionAccess the device's admin interface or check the firmware/build information. Look for 'RTL9601D' or 'Realtek xPON' in the device model and note the software version number.Affected if The device is a Realtek xPON RTL9601D and the software version is exactly 1.9.
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Locate password storage filesAccess the device filesystem via telnet, SSH, or serial console. Search for password configuration files such as /etc/passwd, /etc/shadow, or custom configuration files in /etc/config/, /var/, or the SDK's configuration directories.Affected if Password storage files exist on the RTL9601D device running SDK version 1.9.
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Examine password storage formatOpen the identified password files and inspect the password fields. Check whether passwords appear in plaintext (visible readable text) or in hashed format (alphanumeric strings starting with $ or containing a salt).Affected if Passwords are stored in plaintext rather than being hashed with a secure algorithm.
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Verify network monitoring tool accessibilityCheck for the presence of the built-in network monitoring tool on the device. Look for executable binaries or scripts related to network monitoring in common directories such as /usr/bin/, /bin/, or /sbin/. Attempt to determine if the tool is accessible to non-privileged users.Affected if The network monitoring tool exists and is accessible, allowing retrieval of stored credentials.
A user is affected if they are running the Realtek xPON RTL9601D SDK version 1.9 and their password storage files contain plaintext credentials that can be retrieved via the built-in network monitoring tool.
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 secure password hashing (e.g., bcrypt, scrypt, or Argon2) for all stored credentials and eliminate plaintext storage. Restrict access to the network monitoring tool and audit for similar plaintext storage elsewhere in the SDK.
- Consultation8.0 h
- Implementation16.0 h
- Testing8.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $10,240.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-27372 — 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-2021-27372 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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