CVE Tools

CVE-2025-20215

Cisco Webex Meeting Client Join Certificate Validation Vulnerability

Public exploit available. Not confirmed exploited in the wild yet. A vendor fix is available.

Published Updated Sources: CVE.org, NVD, BDU

What to do

The vendor has published a fix. Version details are below where the sources state them.

What it is

From the CVE record

A vulnerability in the meeting-join functionality of Cisco Webex Meetings could have allowed an unauthenticated, network-proximate attacker to complete a meeting-join process in place of an intended targeted user, provided the requisite conditions were satisfied. Cisco has addressed this vulnerability in the Cisco Webex Meetings service, and no customer action is needed. This vulnerability existed due to client certificate validation issues. Prior to this vulnerability being addressed, an attacker could have exploited this vulnerability by monitoring local wireless or adjacent networks for client-join requests and attempting to interrupt and complete the meeting-join flow as another user who was currently joining a meeting. To successfully exploit the vulnerability, an attacker would need the capability to position themselves in a local wireless or adjacent network, to monitor and intercept the targeted network traffic flows, and to satisfy timing requirements in order to interrupt the meeting-join flow and exploit the vulnerability. A successful exploit could have allowed the attacker to join the meeting as another user. However, the Cisco Product Security Incident Response Team (PSIRT) is not aware of any malicious use of the vulnerability that is described in this advisory.

In plain language

No plain-language summary for this CVE yet.

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS1st
Public exploit
CISA KEV

Not in the catalog. CISA has not confirmed exploitation.

Public exploits

0 sources with a proof of concept or module.

Exploit links, PoCs and Metasploit modules after sign-in
EPSS

0.1% chance of exploitation activity in the next 30 days, which ranks it in the 1st percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Lifecycle

5 events over 0 days, from the signal feeds we watch.

  1. Patch availablepublished, weakness classified, att&ck mapped, record updated

Affected products

And 1 more affected product. See all after sign-in

Technical detail

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

Scored 5.4 by NVD.

How it is reached

  • Attack Vector AdjacentRequires access to the local network (e.g. same Wi-Fi, Bluetooth)
  • Attack Complexity HighRequires specific conditions like a race condition or non-default configuration
  • Privileges Required NoneNo authentication required — anyone can exploit this
  • User Interaction RequiredA user must click a link, open a file, or perform some action

Scope

  • Scope UnchangedImpact is limited to the vulnerable component itself

Impact if exploited

  • Confidentiality HighTotal information disclosure — all data in the component is compromised
  • Integrity LowData modification is possible but limited in scope or consequence
  • Availability NoneNo availability impact

Weaknesses

ATT&CK techniques

Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.

Sources

Watch the software you run.

My Stack ranks new CVEs for your products by real-world exploitation, so the next serious one reaches you without reading every advisory.

We'll flag the next CVE, public exploit or patch for Cisco Webex Meetings, not every advisory. This one: public exploit.

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