CVE-2021-33964
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 · uneditedChina Mobile An Lianbao WF-1 V1.0.1 router provides a web interface /api/ZRRuleFilter/set_firewall_level which receives parameters by POST request, and the parameter firewall_level has a command injection vulnerability. An attacker can use the vulnerability to execute remote 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 China Mobile An Lianbao WF-1 V1.0.1 router has a command injection vulnerability in the /api/ZRRuleFilter/set_firewall_level endpoint. The firewall_level POST parameter is not properly sanitized before being used in system command execution, allowing an attacker to inject arbitrary shell commands.
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= 1.0.1CVSS 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
- 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
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 the device modelAccess the router admin interface or check the device label/marketing material to confirm the model is China Mobile An Lianbao WF-1. This vulnerability affects only this specific router model.Affected if The device model is China Mobile An Lianbao WF-1
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Check the firmware versionLog into the router admin panel and navigate to the system status or firmware version page. Alternatively, check the firmware file metadata or bannergrab the web interface to identify the version number.Affected if The firmware version is exactly 1.0.1
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Verify the API endpoint is accessibleCheck if the router web interface is exposed on the network and if the endpoint /api/ZRRuleFilter/set_firewall_level responds. This can be done by sending a POST request to the endpoint or reviewing proxy/server logs for access attempts.Affected if The endpoint /api/ZRRuleFilter/set_firewall_level is reachable from the network
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Confirm the firewall feature is enabledIn the router admin panel, navigate to the firewall or security settings section. Verify whether the ZRRuleFilter or any firewall rule configuration module is actively enabled on the device.Affected if The firewall or ZRRuleFilter module is enabled on the router
You are affected if you have a China Mobile An Lianbao WF-1 router running firmware version 1.0.1 with the /api/ZRRuleFilter/set_firewall_level endpoint accessible and the firewall feature enabled.
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 the router firmware to a patched version that properly sanitizes input parameters. If no update is available, consider network segmentation or replacing the device.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-33964 — 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-2021-33964 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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- Version or environment caveats, and links to real fixes
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