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Pt 7528 24tx Hv FirmwareOperating system · Moxa

CVE-2020-6989

CRITICAL · 9.8 CVSS v3.1 Published 2020-03-24
Fix available
A fix is available. Upgrade to after 4.0 or later.
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 Moxa PT-7528 series firmware, Version 4.0 or lower, and PT-7828 series firmware, Version 3.9 or lower, a buffer overflow in the web server allows remote attackers to cause a denial-of-service condition or execute arbitrary code.

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 · high confidence

A buffer overflow vulnerability exists in the web server component of Moxa PT-7528 (firmware v4.0 and below) and PT-7828 (firmware v3.9 and below) industrial Ethernet switches. The overflow can be triggered remotely, allowing attackers to cause denial of service or achieve arbitrary code execution.

MitigationUpgrade PT-7528 series firmware to version 4.1 or higher and PT-7828 series firmware to version 4.0 or higher per vendor guidance. If immediate patching is not possible, restrict network access to the web server interface using network segmentation or firewall rules.

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
Pt 7528 24tx Hv FirmwareOperating system
Affected:<= 4.0
Pt 7528 24tx Hv Hv FirmwareOperating system
Affected:<= 4.0
Pt 7528 24tx Wv FirmwareOperating system
Affected:<= 4.0
Pt 7528 24tx Wv Hv FirmwareOperating system
Affected:<= 4.0
Pt 7528 24tx Wv Wv FirmwareOperating system
Affected:<= 4.0
Pt 7528 12msc 12tx 4gsfp Hv FirmwareOperating system
Affected:<= 4.0
Pt 7528 12msc 12tx 4gsfp Hv Hv FirmwareOperating system
Affected:<= 4.0
Pt 7528 12msc 12tx 4gsfp Wv FirmwareOperating system
Affected:<= 4.0

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 Moxa switch model
    Log into the device console or web interface and locate the device information or system status page to confirm the exact model number (PT-7528 or PT-7828 series)
    Affected if The device is a PT-7528 or PT-7828 series industrial Ethernet switch
  2. Check the installed firmware version
    Access the device web interface (System > Firmware Upgrade or About section) or use the console command 'show system info' or 'version' to retrieve the current firmware version
    Affected if The firmware version is 4.0 or lower for PT-7528, or 3.9 or lower for PT-7828
  3. Verify if the web server is enabled
    Navigate to the web server settings in the device configuration (typically under Network > Web Server or System Services) and confirm the HTTP/HTTPS web service is turned on
    Affected if The web server interface is enabled and accessible on the network
  4. Check network exposure of the web interface
    Review firewall rules, VLAN configurations, or ACLs to determine if the device web interface (port 80/443) is reachable from untrusted networks or the internet
    Affected if The web server is exposed to networks outside the trusted management segment

A user is affected if they have a PT-7528 with firmware <=4.0 or PT-7828 with firmware <=3.9, the web server is enabled, and the interface is 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
Upgrade available Upgrade to a release after 4.0
Interim mitigation

Upgrade PT-7528 series firmware to version 4.1 or higher and PT-7828 series firmware to version 4.0 or higher per vendor guidance. If immediate patching is not possible, restrict network access to the web server interface using network segmentation or firewall rules.

Recommended fix Moderate confidence

Firmware version > 4.0 (contact Moxa for exact fixed release)

  1. 1. Identify the exact model number and current firmware version of the affected Moxa PT-7528 device
  2. 2. Download the latest firmware version from the official Moxa support website (moxa.com)
  3. 3. Review the firmware release notes to confirm the version addresses CVE-2020-6989
  4. 4. Backup the current device configuration
  5. 5. Upgrade the firmware following Moxa's documented firmware update procedure for the PT-7528 series
  6. 6. After reboot, verify the new firmware version is installed
  7. 7. Confirm the web server functionality is operational
  8. 8. Validate that the device configuration was preserved or restore from backup
Caveat Industrial network device firmware upgrades may temporarily disrupt network connectivity; test in controlled environment before production deployment

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

Fix this in Pt 7528 24tx Hv Firmware Scoped from the published advisory
  • Consultation3.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,770
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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-2020-6989 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