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En7580 FirmwareOperating system · Mediatek

CVE-2021-31576

HIGH · 7.5 CVSS v3.1 Published 2023-02-06
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
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
In Boa, there is a possible information disclosure due to a missing permission check. This could lead to remote information disclosure to a proximal attacker with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: A20210008; Issue ID: OSBNB00123241.

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 · moderate confidence

In the Boa web server, a missing permission check allows an unauthenticated, proximal attacker (someone on the same network segment) to access sensitive information without any user interaction. The vulnerability enables remote information disclosure with no additional execution privileges required.

MitigationApply patch A20210008 to implement the missing permission check. Until the patch is applied, restrict network access to the Boa server interface to trusted local users only, as exploitation requires a proximal (network-adjacent) attacker.

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
En7580 FirmwareOperating system
Affected:< tlm7.3.275.0-64
En7528 FirmwareOperating system
Affected:< tlm7.3.275.0-64

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
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

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. Check firmware version on Mediatek En7580
    Access the device admin interface or check system information to identify the installed firmware version. Look for a version string like tlm7.x.x.x-64.
    Affected if The firmware version is tlm7.3.275.0-64 or lower.
  2. Check firmware version on Mediatek En7528
    Access the device admin interface or check system information to identify the installed firmware version. Look for a version string like tlm7.x.x.x-64.
    Affected if The firmware version is tlm7.3.275.0-64 or lower.
  3. Verify Boa web server is running and exposed
    Identify processes listening on HTTP ports (typically 80, 443, 8080). Use commands like 'netstat -an' or 'ss -tlnp' to list listening services, or check the device web interface availability.
    Affected if The Boa web server is running and bound to a network interface accessible from untrusted network segments.
  4. Confirm network accessibility to untrusted segments
    Review network configuration to determine if the web server management interface is reachable from network segments outside trusted local users. Check firewall rules, ACLs, or interface bindings.
    Affected if The Boa server interface is accessible to proximal (network-adjacent) attackers without authentication requirements.

A device is affected if it runs Mediatek En7580 or En7528 firmware before version tlm7.3.275.0-64 AND has the Boa web server exposed to untrusted network segments.

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

Apply patch A20210008 to implement the missing permission check. Until the patch is applied, restrict network access to the Boa server interface to trusted local users only, as exploitation requires a proximal (network-adjacent) attacker.

Recommended fix High confidence

tlm7.3.275.0-64

  1. Upgrade En7580 firmware to version tlm7.3.275.0-64 or later
  2. Upgrade En7528 firmware to version tlm7.3.275.0-64 or later
  3. Verify the upgrade was successful and the Boa web server is patched

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

Fix this in En7580 Firmware Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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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-2021-31576 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

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