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Wsr 2533dhpl2 Bk FirmwareOperating system · Buffalo

CVE-2021-20091

HIGH · 8.8 CVSS v3.1 Published 2021-04-29
Fix available
A fix is available. Upgrade to after 1.24 or later.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable 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
The web interfaces of Buffalo WSR-2533DHPL2 firmware version <= 1.02 and WSR-2533DHP3 firmware version <= 1.24 do not properly sanitize user input. An authenticated remote attacker could leverage this vulnerability to alter device configuration, potentially gaining remote code execution.

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

The web interfaces of Buffalo WSR-2533DHPL2 (firmware <= 1.02) and WSR-2533DHP3 (firmware <= 1.24) routers fail to properly sanitize user input. An authenticated attacker can manipulate device configuration through unsanitized parameters, potentially achieving remote code execution on the affected device.

MitigationApply available vendor firmware updates to patch the input sanitization flaw. Until patched, restrict web interface access to trusted users and networks to reduce attack surface.

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
Wsr 2533dhpl2 Bk FirmwareOperating system
Affected:<= 1.02
Wsr 2533dhp3 Bk FirmwareOperating system
Affected:<= 1.24

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
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/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 device model
    Access the router web interface or check the device label to confirm the exact model is Buffalo WSR-2533DHPL2 or WSR-2533DHP3
    Affected if Model is Buffalo WSR-2533DHPL2 or WSR-2533DHP3
  2. Check firmware version on WSR-2533DHPL2
    Log into the router web interface and navigate to the Administration or System section to view the firmware version
    Affected if Firmware version is 1.02 or lower
  3. Check firmware version on WSR-2533DHP3
    Log into the router web interface and navigate to the Administration or System section to view the firmware version
    Affected if Firmware version is 1.24 or lower
  4. Verify web interface accessibility
    Confirm the router web management interface is reachable on the local network or remotely
    Affected if Web interface is exposed and accessible
  5. Check authentication requirements
    Confirm that authentication is required to access configuration parameters in the web interface
    Affected if Web interface permits authenticated access to configuration functions

The device is affected if it is a Buffalo WSR-2533DHPL2 with firmware <=1.02 or WSR-2533DHP3 with firmware <=1.24, and its web interface is accessible with valid credentials.

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 1.24
Interim mitigation

Apply available vendor firmware updates to patch the input sanitization flaw. Until patched, restrict web interface access to trusted users and networks to reduce attack surface.

Recommended fix Moderate confidence

Firmware version > 1.02 for WSR-2533DHPL2 or > 1.24 for WSR-2533DHP3 (check Buffalo's official support page for the exact latest release)

  1. 1. Identify the exact model number of your Buffalo WSR-2533 router (WSR-2533DHPL2 or WSR-2533DHP3)
  2. 2. Visit the official Buffalo support website to check for available firmware updates
  3. 3. Download the latest firmware version available for your specific model
  4. 4. Access the router's web interface using administrative credentials
  5. 5. Navigate to the firmware update or administration section
  6. 6. Upload and apply the new firmware version
  7. 7. After the update completes, verify the new firmware version is installed
  8. 8. Confirm the vulnerability is resolved by checking that the new version is greater than 1.02 for WSR-2533DHPL2 or greater than 1.24 for WSR-2533DHP3
Caveat Review Buffalo's firmware release notes for any configuration or compatibility changes before upgrading

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

Fix this in Wsr 2533dhpl2 Bk Firmware Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,240
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.

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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-2021-20091 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