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En7580 FirmwareOperating system · Mediatek

CVE-2021-31578

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 stack buffer overflow. 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

Stack buffer overflow in Boa web server allows a proximal network attacker to achieve remote privilege escalation without any user interaction. The vulnerability stems from insufficient bounds checking in the affected code path, enabling potential arbitrary code execution.

MitigationApply patch A20210008 or update to the patched version of Boa to remediate the stack buffer overflow vulnerability.

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 Mediatek firmware version
    Access the device CLI or check the system information page. Run 'cat /proc/version' or 'uname -a' to retrieve the firmware build string, or view the firmware version displayed in the device admin interface under 'Status' or 'System Information'.
    Affected if The displayed firmware version string contains a build number lower than tlm7.3.275.0-64 (for example, tlm7.3.200.0-64 or earlier).
  2. Confirm the device model is vulnerable
    Check the device model or SoC identifier in the system information. The affected models are En7580 and En7528.
    Affected if The device uses a Mediatek En7580 or En7528 chipset.
  3. Verify Boa web server is enabled and running
    Check for the boa process using 'ps | grep boa' or check open network ports using 'netstat -tuln' looking for port 80 or 443. If the web interface is accessible, Boa is running.
    Affected if The Boa process is actively running or the web server on ports 80/443 is responding to HTTP requests.
  4. Assess network exposure of the web service
    Check the network configuration to determine if the web server is bound to a WAN-facing IP address. Use 'iptables -L -n' or check the device's firewall rules to see if port 80/443 is exposed to the internet.
    Affected if The Boa web server is accessible from external/network-facing interfaces without filtering.

The device is affected if it runs Mediatek En7580 or En7528 firmware with a build version lower than tlm7.3.275.0-64 AND the Boa web server is actively running and network-accessible.

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 or update to the patched version of Boa to remediate the stack buffer overflow vulnerability.

Recommended fix High confidence

tlm7.3.275.0-64

  1. 1. Identify the MediaTek device model (En7580 or En7528)
  2. 2. Navigate to the device's administrative web interface or access via TFTP/serial for firmware update
  3. 3. Obtain the firmware version tlm7.3.275.0-64 from MediaTek's official firmware repository
  4. 4. Upload and apply the firmware update to the device
  5. 5. Verify the firmware version has been successfully updated to tlm7.3.275.0-64
  6. 6. Reboot the device to ensure the new firmware is running
Caveat Firmware upgrades may reset device configuration to defaults; backup current settings before upgrading

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-2021-31578 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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