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Webex Meetings OnlineApplication · Cisco

CVE-2020-3116

MEDIUM · 5.5 CVSS v3.1 Published 2020-09-23
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
58/100
Remediation priority · Elevated
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
A vulnerability in the way Cisco Webex applications process Universal Communications Format (UCF) files could allow an attacker to cause a denial of service (DoS) condition. The vulnerability is due to insufficient validation of UCF media files. An attacker could exploit this vulnerability by sending a user a malicious UCF file through a link or email attachment and persuading the user to open the file with the affected software on the local system. A successful exploit would cause the application to quit unexpectedly.

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

A vulnerability in Cisco Webex applications allows denial of service via malicious Universal Communications Format (UCF) files. The vulnerability exists due to insufficient validation of UCF media files during processing. An attacker can exploit this by sending a specially crafted UCF file (via link or email attachment) that causes the Webex application to crash when opened by the victim.

MitigationApply available Cisco patches for Webex applications. Until patched, warn users not to open UCF files from untrusted sources. Consider blocking UCF file attachments at the email gateway as a defense-in-depth measure.

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
Webex Meetings OnlineApplication
Affected:= 1.3.43
Webex Meetings ServerApplication
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
Local
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/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 installed Webex Meetings version
    On Windows, open the Webex desktop app, go to Help > About Cisco Webex Meetings, or check Add/Remove Programs. On Mac, check the Applications folder or use the Webex app menu.
    Affected if The installed version matches or falls within the affected version ranges (Webex Meetings Online version 1.3.43 and earlier, or Webex Meetings Server version 4.0 and earlier)
  2. Determine if UCF file handling is available in Webex
    Check if Webex is configured to handle or play Universal Communications Format (UCF) files. This is typically a default capability for playing recordings or archived meetings. Look in Webex site settings or player preferences for UCF-related options.
    Affected if UCF file processing is enabled and the Webex version is within the affected range
  3. Verify Webex Meetings Server version if applicable
    If using an on-premises Webex Meetings Server, access the Webex server administration interface or check the version information in the server management console.
    Affected if The server version is 4.0 or earlier and UCF file processing features are enabled

A user is affected if they have a vulnerable Webex Meetings version (Online 1.3.43 and earlier, or Meetings Server 4.0 and earlier) AND the application is capable of processing UCF files, which can be triggered by opening a malicious UCF file.

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

Apply available Cisco patches for Webex applications. Until patched, warn users not to open UCF files from untrusted sources. Consider blocking UCF file attachments at the email gateway as a defense-in-depth measure.

Fix this in Webex Meetings Online Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing3.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,570
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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-2020-3116 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