CVE-2020-6870
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 · uneditedThe version V12.17.20T115 of ZTE U31R20 product is impacted by a design error vulnerability. An attacker could exploit the vulnerability to log in to the FTP server to tamper with the password, and illegally download, modify, upload, or delete files, causing improper operation of the network management system and equipment. This affects: NetNumenU31R20 V12.17.20T115
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 · moderate confidenceA design error in ZTE NetNumenU31R20 V12.17.20T115 allows unauthorized access to the embedded FTP server. Attackers can log in without proper authentication and perform file operations (download, modify, upload, delete), potentially compromising the network management system and managed equipment.
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= v12.17.20t115CVSS 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
- Adjacent
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:A/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 product and firmware versionAccess the device management interface or check system information page to confirm the product is ZTE NetNumen U31 R20 and record the firmware versionAffected if The firmware version matches v12.17.20t115 exactly
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Locate the FTP service statusCheck the device network services or running services list to see if the FTP server is enabledAffected if FTP server is currently enabled on the device
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Verify FTP authentication configurationAttempt to connect to the FTP service using an IP address or hostname of the device. Try logging in with no username, anonymous, or blank password to test if authentication is requiredAffected if FTP allows login without valid credentials (anonymous access works or no password is accepted)
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Confirm FTP write access availabilityUsing an unauthenticated FTP session, attempt to list directories or perform a test file operation such as retrieving a fileAffected if File operations (download, upload, modify, delete) are accessible without authentication
The device is affected if it runs ZTE NetNumen U31 R20 firmware version v12.17.20t115 and has the FTP service enabled with authentication bypass vulnerability.
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 patch if available; otherwise disable the FTP service or restrict access via firewall/ACLs, and migrate to secure file transfer protocols (SFTP/SCP).
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 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 $6,176.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-6870 — 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-2020-6870 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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