Cisco Webex Meeting Client Join Certificate Validation Vulnerability

TL;DR 📌

A medium-severity vulnerability in the Cisco Webex Meeting Client could allow an unauthenticated attacker on a local network to join meetings as another user. Cisco has addressed this issue, and no user action is required.

What happened 🕵️‍♂️

A vulnerability was identified in the meeting-join functionality of Cisco Webex Meetings. This flaw could permit an unauthenticated, network-proximate attacker to impersonate a legitimate user during the meeting-join process. The vulnerability arises from issues with client certificate validation, allowing an attacker to intercept and complete a meeting-join flow if they are positioned on a local or adjacent network. Cisco has confirmed that there is no known malicious exploitation of this vulnerability.

Affected products 🖥️

The vulnerability affects the Cisco Webex Meetings service, which is cloud-based.

Fixed software 🔧

Upgrade to the first fixed release in your train (or later):

Workarounds 🧯

There are no workarounds that address this vulnerability.

Risk in context 🎯

With a CVSS score of 5.4, this vulnerability is rated as Medium. The risk is primarily associated with local network exposure, as an attacker would need to be on the same or adjacent network to exploit the vulnerability. While the potential for exploitation exists, Cisco’s Product Security Incident Response Team (PSIRT) has not reported any known instances of this vulnerability being exploited in the wild.

Fast facts ⚡

• Vulnerability: Cisco Webex Meeting Client Join Certificate Validation
• CVSS Score: 5.4 (Medium)
• Exploitation: Requires local network access
• Impact: Allows impersonation of another user during meeting join
• Fix: No user action required; vulnerability addressed by Cisco

For leadership 🧭

This vulnerability in the Cisco Webex Meeting Client has a Medium risk rating (CVSS 5.4). It requires an attacker to be on a local network, which limits exposure but still poses a risk of unauthorized access to meetings. Cisco has resolved the issue, and no immediate action is required from users.

Remediation ask: No action needed; the vulnerability has been addressed.

Operational impact: No expected downtime or configuration changes.

Now / Next / Later:

• Now: Confirm awareness of the vulnerability and its resolution.
• Next: Monitor for any updates from Cisco regarding security advisories.
• Later: Review network security policies to mitigate risks associated with local network access.