CVE-2021-39999
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 · uneditedThere is a buffer overflow vulnerability in eSE620X vESS V100R001C10SPC200 and V100R001C20SPC200. An attacker can exploit this vulnerability by sending a specific message to the target device due to insufficient validation of packets. Successful exploit could cause a denial of service condition.
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 confidenceBuffer overflow vulnerability in eSE620X vESS devices (V100R001C10SPC200 and V100R001C20SPC200) due to insufficient validation of incoming packets. An attacker can send a specifically crafted message to trigger the overflow, causing denial of service.
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= v100r001c10spc200= v100r001c20spc200CVSS 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
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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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Confirm device model is eSE620X vESSAccess the device management interface or CLI and retrieve the device model information from the system status or device info page. Look for 'eSE620X' or 'vESS' in the model identification.Affected if Device model is Huawei eSE620X vESS series.
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Check installed firmware versionIn the device web interface, navigate to System > Firmware or use the CLI command 'display version' to retrieve the current firmware version. Compare the version string against the affected releases.Affected if Firmware version equals v100r001c10spc200 or v100r001c20spc200.
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Verify network accessibility of the deviceReview network configuration to determine if the vESS management interface is reachable from untrusted networks. Check firewall rules and access control lists that govern traffic to the device.Affected if Device management interface is exposed to untrusted or internet-facing networks without proper filtering.
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Check for service disruption indicatorsReview system logs, network traffic logs, and device availability status. Look for unexpected device reboots, crashes, or abnormal service interruptions that may indicate exploitation.Affected if Device has experienced unexplained denial of service events or crashes coinciding with receipt of malformed packets.
A user is affected if they operate an eSE620X vESS device running firmware version v100r001c10spc200 or v100r001c20spc200 that is network-accessible to potential attackers.
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 dataApply vendor firmware patch when available; until then, isolate affected devices on restricted network segments and implement firewall rules to limit exposure to untrusted sources.
- Consultation6.0 h
- Implementation12.0 h
- Testing6.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $7,680.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-39999 — 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-2021-39999 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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