CyberSecBulletin
CVE-2022-27178NVD status: Modified

LinkHub Mesh Wifi: Improper Access Control

CVE-2022-27178 is a critical-severity improper access control vulnerability in LinkHub Mesh Wifi from Tcl, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected LinkHub Mesh Wifi versions: MS1G_00_01.00_14. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.2% chance of exploitation within 30 days, higher than 69% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of LinkHub Mesh Wifi you run against the affected versions below, and install the vendor's latest release.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
TCLLinkHub Mesh WifiMS1G_00_01.00_14Not stated
TclLinkhub Mesh WiFi Ac1200ms1g_00_01.00_14Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.19.8CriticalNVD
CVSS 3.09.6CriticalCNA (cisco.com)

Official description

A denial of service vulnerability exists in the confctl_set_wan_cfg functionality of TCL LinkHub Mesh Wi-Fi MS1G_00_01.00_14. A specially-crafted network packet can lead to denial of service. An attacker can send packets to trigger this vulnerability.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Access Control

The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.

How developers prevent this class of flaw

  • Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
  • Compartmentalize the system to have safe areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

More Improper Access Control vulnerabilities (CWE-284)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Technical write-ups (may include proof of concept)

Other vulnerabilities in LinkHub Mesh Wifi

All LinkHub Mesh Wifi vulnerabilities

Recent Improper Access Control vulnerabilities

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