Security readout for executives and security teams
Plain-English summary
During initial setup, the Meross MSS550X wall switch can expose the user’s Wi-Fi name and password because the setup access point and HTTP/JSON traffic lack required protection. An attacker who can interact with that setup flow could learn network credentials. No provided source shows active exploitation.
Executive priority
Treat this as a targeted confidentiality risk to Wi-Fi credentials, not a broad remote takeover issue. Prioritize if these switches are used on business networks or were configured in uncontrolled locations.
Technical view
CVE-2021-3774 affects Meross Smart Wi-Fi 2 Way Wall Switch MSS550X firmware 3.1.3 and earlier. The setup process creates an open Wi-Fi access point and sends configured SSID and password in plaintext HTTP/JSON. CVSS 3.1 is 7.4 high: network attack vector, low complexity, no privileges, user interaction required, confidentiality impact high.
Likely exposure
Exposure is likely limited to organizations or homes using Meross MSS550X switches during initial onboarding or reconfiguration. Risk is highest where setup occurs near untrusted wireless users or shared spaces.
Exploitation context
The source bundle does not identify public exploit code, mass exploitation, or CISA KEV listing. The attack depends on user interaction during setup and access to the device’s insecure onboarding communication.
Researcher notes
Evidence is based on the CVE record and INCIBE advisory reference. The affected condition is the initial setup path, not normal authenticated device operation. The bundle does not name a fixed version or mitigation beyond the vulnerable firmware boundary.
Mitigation direction
- Inventory Meross MSS550X switches and identify firmware versions.
- Check Meross or INCIBE guidance for fixed firmware before continued deployment.
- Avoid onboarding affected devices on sensitive production Wi-Fi.
- Rotate Wi-Fi credentials if setup occurred in an untrusted wireless environment.
- Replace or retire affected devices if no vendor fix is available.
Validation and detection
- Confirm whether any MSS550X devices run firmware 3.1.3 or earlier.
- Review procurement and asset records for Meross MSS550X deployments.
- Check whether recent onboarding occurred in public or shared wireless environments.
- Verify vendor guidance for patched firmware or supported remediation.
- Document any Wi-Fi credential rotation after suspected exposure.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
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CWE-319: Exact CWE lookup
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Open ATT&CK lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-3774 mapping review
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Open ATT&CK lookup- Severity
- High
- CVSS
- 7.4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N2.84Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.4HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://www.incibe.es/en/incibe-cert/notices/aviso/meross-mss550x-missing-encryption-sensitive-dataCVE reference · x_refsource_CONFIRM
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Cleartext Transmission of Sensitive Information
Cleartext Transmission of Sensitive Information represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.