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MicollabApplication · Mitel

CVE-2021-27401

MEDIUM · 6.1 CVSS v3.1 Published 2021-08-13
Fix available
A fix is available. Upgrade to 9.2 or later.
See remediation →
68/100
Remediation priority · Elevated
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
The Join Meeting page of Mitel MiCollab Web Client before 9.2 FP2 could allow an attacker to access (view and modify) user data by executing arbitrary code due to insufficient input validation, aka Cross-Site Scripting (XSS).

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

Mitel MiCollab Web Client versions before 9.2 FP2 contain a reflected Cross-Site Scripting (XSS) vulnerability in the Join Meeting page. Due to insufficient input validation, an attacker can inject malicious JavaScript code through unsanitized input parameters, allowing execution of arbitrary client-side code to view and modify user data.

MitigationUpdate MiCollab Web Client to version 9.2 FP2 or later. Additionally, implement proper input validation and output encoding on all user-facing fields in the Join Meeting page.

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
MicollabApplication
Affected:< 9.2= 9.2

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
Changed
Confidentiality
Low
Integrity
Low
Availability
None

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

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 MiCollab Web Client installed version
    Locate the MiCollab server or web client installation and retrieve the version number from the application metadata, admin console, or about page. Common locations include the system administration interface or the installer package information.
    Affected if The version retrieved is 9.2 or any version below 9.2 (e.g., 9.1, 9.0, earlier versions)
  2. Confirm Join Meeting feature is accessible
    Verify that the Join Meeting functionality is enabled and accessible to users in the MiCollab deployment. Check via the web client interface or admin configuration.
    Affected if The Join Meeting page is available and exposed to end users
  3. Check Join Meeting page input handling
    Inspect the Join Meeting page for input parameters (such as meeting IDs or user names) and verify whether proper input validation and output encoding are implemented. Look for unvalidated query parameters or form inputs.
    Affected if User-supplied input in Join Meeting parameters is reflected back without sanitization or encoding
  4. Review web server logs for suspicious Join Meeting requests
    Examine web server and application logs for anomalous patterns in Join Meeting page access, particularly requests containing script tags or unusual characters in input fields.
    Affected if Logs show evidence of injected script content in Join Meeting request parameters

You are affected if the MiCollab Web Client version is 9.2 or below and the Join Meeting page is accessible with unsanitized input parameters.

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 9.2 or later
Fixed in 9.2
Interim mitigation

Update MiCollab Web Client to version 9.2 FP2 or later. Additionally, implement proper input validation and output encoding on all user-facing fields in the Join Meeting page.

Recommended fix Moderate confidence

9.2 Feature Pack 2 (FP2) or later

  1. 1. Identify the current version of Mitel MiCollab Web Client installed in your environment
  2. 2. Download Mitel MiCollab version 9.2 Feature Pack 2 (FP2) or later from the official Mitel support portal
  3. 3. Review MiCollab upgrade documentation and release notes for prerequisites
  4. 4. Schedule a maintenance window to perform the upgrade
  5. 5. Backup current configuration data before proceeding with the upgrade
  6. 6. Apply the upgrade following Mitel's standard upgrade procedures
  7. 7. Verify the upgrade was successful and test the Join Meeting functionality

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

Fix this in Micollab Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing5.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,790
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,464.

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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-2021-27401 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