Security readout for executives and security teams
Plain-English summary
Some Enbra Wireless M-Bus meters and related EWM software use a built-in encryption key that cannot be changed. If an attacker is close enough to interact with the wireless bus, they may be able to read information available in Enbra EWM. The issue is confidentiality-focused, not an integrity or availability flaw in the supplied record.
Executive priority
Treat this as a moderate confidentiality risk for affected Enbra deployments. Prioritize environments where meter data is sensitive, deployed in publicly accessible areas, or broadly reachable by nearby wireless access. There is no supplied evidence of active exploitation, but hard-coded unchangeable credentials usually require vendor-driven remediation or replacement planning.
Technical view
CVE-2021-34571 is CWE-798 hard-coded credentials in Enbra Wireless M-Bus Security mode 5. CVSS 3.1 is 6.5 with adjacent attack vector, low complexity, no privileges, no user interaction, and high confidentiality impact. Affected products include AT-WMBUS-16-2, ER-AM DN 15/SV and /TV, and EWM 1.7.29 dated 03.11.2019.
Likely exposure
Exposure is most likely in organizations operating the listed Enbra Wireless M-Bus devices or EWM version in field deployments. Risk depends on whether an unauthorized party can get adjacent wireless proximity. The supplied sources do not indicate internet exposure, integrity impact, availability impact, or affected products beyond the named Enbra devices and version.
Exploitation context
The source bundle does not report active exploitation, and the CVE is not marked as KEV. The practical concern is nearby wireless access to systems using a non-changeable key. Public evidence supports data exposure risk, but not exploit availability, observed campaigns, or remote internet exploitation.
Researcher notes
The record is narrow: hard-coded credentials in Security mode 5 with confidentiality impact only. Avoid expanding scope beyond the listed Enbra products and versions. No patch, fixed version, exploit status, or campaign evidence is provided in the supplied sources, so validation should focus on asset matching and exposure conditions.
Mitigation direction
- Inventory Enbra Wireless M-Bus devices and EWM installations against the affected product list.
- Check Enbra or supplier guidance for replacement, upgrade, or operational remediation options.
- Reduce unauthorized physical and radio proximity to affected deployments where feasible.
- Limit collection or retention of sensitive data exposed through affected EWM workflows.
- Document compensating controls if affected devices cannot be replaced promptly.
Validation and detection
- Confirm model names and EWM version/date from asset records, labels, or management interfaces.
- Verify whether Wireless M-Bus Security mode 5 is in use on affected deployments.
- Confirm whether the encryption key can be changed; the CVE states it cannot.
- Assess who can get adjacent wireless proximity to each affected deployment.
- Record business data types exposed through Enbra EWM for impact analysis.
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
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-798: Credential and account abuse lookup
Authentication and credential weaknesses can make valid-account abuse and credential telemetry useful review starting points. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-34571 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/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:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N2.83.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.5MediumVector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://www.fit.vutbr.cz/~polcak/CVE-2021-34571.enCVE 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.
Use of Hard-coded Credentials
Use of Hard-coded Credentials represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.