CVE-2021-3774Network attack vector

Wi-Fi credential disclosure via plaintext setup requests

Published Nov 5, 2021 · Updated Apr 23, 2025

Cleartext transmission in Meross Smart Wi-Fi 2-Way Wall Switch 3.1.3 and earlier allows remote attackers to read Wi-Fi credentials. During initial setup, the app sends the selected SSID and password to the switch in an unencrypted HTTP/JSON request over an open Wi-Fi access point. Access requires proximity to that setup network and user interaction that triggers transmission; the reported consequence is credential disclosure only.

CVSS severity6.5
Medium
EPSS probability0.73%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Cleartext transmission in Meross Smart Wi-Fi 2-Way Wall Switch 3.1.3 and earlier allows remote attackers to read Wi-Fi credentials. During initial setup, the app sends the selected SSID and password to the switch in an unencrypted HTTP/JSON request over an open Wi-Fi access point. Access requires proximity to that setup network and user interaction that triggers transmission; the reported consequence is credential disclosure only.

The record

CVE
CVE-2021-3774
Published
Nov 5, 2021
Updated
Apr 23, 2025
Vendor
Meross
Product
Meross Smart Wi-Fi 2-Way Wall Switch
Classifications
CWE-319, T1040
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 5, 2021CVE publishedPublication date reported by the CVE source.
  2. Apr 23, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=3.1.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Meross · Meross Smart Wi-Fi 2-Way Wall Switchversion=0 <=3.1.3

Published CVSS scores

7.4INCIBECVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N
6.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
4.3NVDAV:N/AC:M/Au:N/C:P/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-319Cleartext Transmission of Sensitive Information
T1040Network Sniffing

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo