dbcve.org
Ar FirmwareOperating system · Huawei

CVE-2016-6901

MEDIUM · 6.5 CVSS v3.0 Published 2016-09-26
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable Zero-click

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 · unedited
Format string vulnerability in Huawei AR100, AR120, AR150, AR200, AR500, AR550, AR1200, AR2200, AR2500, AR3200, and AR3600 routers with software before V200R007C00SPC900 and NetEngine 16EX routers with software before V200R007C00SPC900 allows remote authenticated users to cause a denial of service via format string specifiers in vectors involving partial 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 confidence

A format string vulnerability exists in Huawei AR series routers and NetEngine 16EX devices running software versions prior to V200R007C00SPC900. The flaw allows remote authenticated users to inject format string specifiers (such as %s, %x, %n) into partial commands, causing the device to misinterpret user input as format strings rather than data. This leads to information disclosure, memory corruption, or denial of service via device crash.

MitigationUpgrade router firmware to version V200R007C00SPC900 or later. Until patching is feasible, restrict administrative access to trusted personnel only and monitor for anomalous command patterns containing format string characters.

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
Ar FirmwareOperating system
Affected:= v200r005= v200r006= v200r007c00
Netengine 16ex FirmwareOperating system
Affected:= v200r005= v200r006= v200r007c00

CVSS 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
None
Integrity
None
Availability
High

CVSS:3.0/AV:N/AC:L/PR:L/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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify device model and firmware version
    Log into the device CLI and execute 'display version' or access the web management interface to view the device information page. Note the exact model (AR series or NetEngine 16EX) and firmware version string.
    Affected if The device is a Huawei AR series router or NetEngine 16EX and the firmware version is v200r005, v200r006, or v200r007c00 (any version prior to V200R007C00SPC900).
  2. Verify management access exposure
    Check the current service configurations using 'display current-configuration | include telnet|ssh|http|https' in CLI or review the web interface access settings. Note which management protocols are enabled and from which IP addresses they accept connections.
    Affected if Telnet, SSH, HTTP, or HTTPS management interfaces are exposed to untrusted networks or IP addresses, allowing remote authenticated attackers to send malicious commands.
  3. Check for format string injection attempts
    Review device logs using 'display logbuffer' or check the syslog server for recent entries containing pattern '%s', '%x', '%n', or '0x' in command inputs. Look for entries indicating malformed command parsing or unexpected output.
    Affected if Logs show unusual command patterns containing format string specifiers or indicate the device is processing format characters as formatting directives rather than literal data.
  4. Confirm authentication method and user access
    Execute 'display user-interface' or 'display local-user' to view configured administrative accounts and their privilege levels. Check if weak or default credentials are in use.
    Affected if The device allows remote administrative authentication through accessible management interfaces, enabling authenticated attackers to inject format strings via partial commands.

The device is affected if it is a Huawei AR series router or NetEngine 16EX running firmware version v200r005, v200r006, or v200r007c00 (any version prior to V200R007C00SPC900) and has exposed management interfaces that allow remote authenticated users to submit commands.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade router firmware to version V200R007C00SPC900 or later. Until patching is feasible, restrict administrative access to trusted personnel only and monitor for anomalous command patterns containing format string characters.

Fix this in Ar Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,120.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2016-6901 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2016-6901 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • 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