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En7580 FirmwareOperating system · Mediatek

CVE-2021-31577

CRITICAL · 9.8 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 →
100/100
Remediation priority · Urgent
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 escalation of privilege due to a missing permission check. This could lead to remote escalation of privilege from 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 Boa web server, a missing permission check allows a proximal attacker to escalate privileges remotely without user interaction or additional execution privileges, achieving critical severity (CVSS 9.8).

MitigationApply patch A20210008 to implement proper permission checks in Boa, and verify the fix does not introduce authentication/authorization bypasses for legitimate users.

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
High
Availability
High

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

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. Identify the device model
    Check the hardware model or SoC identifier of the device (e.g., via /proc/cpuinfo, u-boot env, or device label) to confirm it is a Mediatek En7580 or En7528
    Affected if The device is NOT an En7580 or En7528 (not affected)
  2. Determine the firmware version
    Check the installed firmware version via the device's web UI, bootloader, or by reading /etc/version, /etc/build, or similar version file on the device filesystem
    Affected if The firmware version is tlm7.3.275.0-64 or higher (not vulnerable)
  3. Confirm firmware version is below threshold
    Compare your installed firmware version against the affected range: any version lower than tlm7.3.275.0-64 is vulnerable
    Affected if Firmware version is less than tlm7.3.275.0-64 AND the device model is En7580 or En7528
  4. Verify Boa web server is accessible
    Check if the Boa HTTP service is exposed on the device by attempting to access its web interface (typically ports 80/443) or by checking running processes for the boa binary
    Affected if Boa is not running or not network-accessible (reduced attack surface)

A device is affected if it is a Mediatek En7580 or En7528 running firmware versions lower than tlm7.3.275.0-64 with the Boa web server accessible on the network.

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 proper permission checks in Boa, and verify the fix does not introduce authentication/authorization bypasses for legitimate users.

Recommended fix High confidence

tlm7.3.275.0-64 or later for En7580/En7528

  1. 1. Identify the specific MediaTek device model (En7580 or En7528) that needs remediation
  2. 2. Check the current firmware version installed on the device
  3. 3. Navigate to MediaTek's official firmware support portal (corp.mediatek.com or authorized download channels)
  4. 4. Download firmware version tlm7.3.275.0-64 or later for the specific device model
  5. 5. Follow the device-specific firmware update procedure (typically via web UI, TFTP, or vendor provisioning tool)
  6. 6. Verify the firmware was successfully applied by checking the new version number
  7. 7. Confirm the Boa service is functioning normally after update

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
  • Testing6.0 h
  • Review / QA3.0 h
15.0 hours of engineering $2,560
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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-2021-31577 in production — separate from our analysis above.

No notes yet

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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
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data