dbcve.org
Optical Bb Unit E Wmta FirmwareOperating system · Softbank

CVE-2021-20783

HIGH · 8.8 CVSS v3.1 Published 2021-07-30
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
95/100
Remediation priority · Urgent
Remotely reachable No privileges

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
Cross-site request forgery (CSRF) vulnerability in Optical BB unit E-WMTA2.3 allows a remote attacker to hijack the authentication of administrators via a specially crafted page.

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

Cross-site request forgery (CSRF) vulnerability in the Optical BB unit E-WMTA2.3 allows remote attackers to trick administrators into performing unintended actions by embedding malicious requests in specially crafted web pages, potentially hijacking administrative authentication sessions.

MitigationImplement anti-CSRF tokens for state-changing operations, validate Origin/Referer headers, and apply any available firmware updates from the device vendor; until patched, administrators should avoid clicking untrusted links while authenticated.

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
Optical Bb Unit E Wmta FirmwareOperating system
Affected:= 2.3

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
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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 firmware version
    Access the device's administrative web interface or check via SNMP/command line interface to determine the installed firmware version. Look for a version display in the system status or diagnostics section.
    Affected if The firmware version is exactly 2.3 (E-WMTA2.3)
  2. Confirm the web management interface is enabled
    Verify that the HTTP/HTTPS administrative web interface is accessible on the device. This is typically accessible on the LAN or WAN interface depending on configuration.
    Affected if The web-based administrative interface is active and reachable

The environment is affected only if the device runs firmware version 2.3 AND has the web administrative interface enabled, as CSRF requires an authenticated admin session to exploit.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Implement anti-CSRF tokens for state-changing operations, validate Origin/Referer headers, and apply any available firmware updates from the device vendor; until patched, administrators should avoid clicking untrusted links while authenticated.

Fix this in Optical Bb Unit E Wmta Firmware Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,560.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-20783 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2021-20783 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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