CVE-2021-1221: Cisco Webex Meetings and Cisco Webex Meetings Server Software Hyperlink Injection Vulnerability

Severity: medium (CVSS 4.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.0% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-02-04 · updated 2026-06-17
Weakness: CWE-20

Description

A vulnerability in the user interface of Cisco Webex Meetings and Cisco Webex Meetings Server Software could allow an authenticated, remote attacker to inject a hyperlink into a meeting invitation email. The vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by entering a URL into a field in the user interface. A successful exploit could allow the attacker to generate a Webex Meetings invitation email that contains a link to a destination of their choosing. Because this email is sent from a trusted source, the recipient may be more likely to click the link.

Affected products

Cisco Webex Meetings: before 41.1.0 — fixed in 41.1.0
Cisco WebEx Meetings Server: before 3.0; 3.0, 3.0-maintenance_release3_security_patch4, 4.0, 4.0-maintenance_release3_security_patch3 — fixed in 3.0

How to fix

Upgrade to a fixed version: Cisco Webex Meetings 41.1.0; Cisco WebEx Meetings Server 3.0. Check the vendor advisory for mitigations.

References

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