dbcve.org
Wifi Repeater FirmwareOperating system · Twsz

CVE-2017-8772

CRITICAL · 9.8 CVSS v3.0 Published 2017-09-20
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges 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
On BE126 WIFI repeater 1.0 devices, an attacker can log into telnet (which is open by default) with default credentials as root (username:"root" password:"root") and can: 1. Read the entire file system; 2. Write to the file system; or 3. Execute any code that attacker desires (malicious or not).

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

The BE126 WIFI repeater 1.0 ships with telnet service enabled by default and uses hardcoded default credentials (root/root), allowing any network-adjacent attacker to gain unauthenticated root access to the device's embedded Linux firmware. This provides full read/write filesystem access and arbitrary code execution capabilities.

MitigationImmediately change the default telnet credentials to strong, unique values, and disable the telnet service if not operationally required. If a firmware update is available from the vendor, apply it to address this and any other known vulnerabilities.

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
Wifi Repeater FirmwareOperating system
Affected:all versions

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
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/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 checks

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

  1. Identify the device model and firmware
    Check the device label, web interface, or SSH into the device and run commands like 'cat /proc/cpuinfo', 'uname -a', or check the web interface header/footer for model information
    Affected if The device is a BE126 WIFI repeater or runs Twsz Wifi Repeater Firmware (all versions)
  2. Verify telnet service is listening
    From a network-adjacent system, run 'telnet <device-ip>' or use a port scanner (e.g., 'nmap -p 23 <device-ip>') to check if port 23 is open and responding
    Affected if Port 23/telnet is open and accepts connections on the device
  3. Test default credentials
    Connect to the open telnet port and attempt login with username 'root' and password 'root'
    Affected if The credentials root/root successfully authenticate and provide root shell access
  4. Check telnet service configuration
    If you have shell access (via telnet or other means), inspect startup scripts or configuration files (e.g., /etc/init.d/, /etc/inetd.conf, /etc/config/) for telnet-related entries
    Affected if Telnet service is configured to start automatically on boot or is enabled in the firmware

If the device is a BE126 WIFI repeater or Twsz Wifi Repeater with telnet port 23 open and default credentials root/root still active, the environment is affected by this vulnerability.

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.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Immediately change the default telnet credentials to strong, unique values, and disable the telnet service if not operationally required. If a firmware update is available from the vendor, apply it to address this and any other known vulnerabilities.

Recommended fix Low confidence
  1. Disable the telnet service on the device if the firmware provides a configuration option to do so
  2. If telnet cannot be disabled through firmware settings, block incoming TCP port 23 at the network perimeter firewall or router to prevent external telnet access
  3. Isolate the WiFi repeater on a separate VLAN or restricted network segment to limit exposure if compromise occurs
  4. If remote management is not required, disable it entirely in the device firmware settings
  5. Monitor network traffic for unusual outbound connections from the device subnet

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Wifi Repeater Firmware Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,130
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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-2017-8772 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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