CVE-2021-1420: A vulnerability in certain web pages of Cisco Webex Meetings could allow an unauthenticated, remote attacker to modify a web page in the context of a ...

Description

A vulnerability in certain web pages of Cisco Webex Meetings could allow an unauthenticated, remote attacker to modify a web page in the context of a user's browser. The vulnerability is due to improper checks on parameter values in affected pages. An attacker could exploit this vulnerability by persuading a user to follow a crafted link that is designed to pass HTML code into an affected parameter. A successful exploit could allow the attacker to alter the contents of a web page to redirect the user to potentially malicious websites, or the attacker could use this vulnerability to conduct further client-side attacks.

Metrics

CVSS 3.1

4.7/10

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

EPSS Probability

0.92%

55.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-80

Affected Software

Vendor	Product	Versions
Cisco	Webex Meetings	All versions

References

Timeline

Published: Apr 8, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-1420?

A vulnerability in certain web pages of Cisco Webex Meetings could allow an unauthenticated, remote attacker to modify a web page in the context of a user's browser. The vulnerability is due to improper checks on parameter values in affected pages. An attacker could exploit this vulnerability by persuading a user to follow a crafted link that is designed to pass HTML code into an affected parameter. A successful exploit could allow the attacker to alter the contents of a web page to redirect the user to potentially malicious websites, or the attacker could use this vulnerability to conduct further client-side attacks.

How severe is CVE-2021-1420?

CVE-2021-1420 has a CVSS score of 4.7/10 (MEDIUM severity). The EPSS model estimates a 0.92% probability of exploitation in the next 30 days.

How do I fix CVE-2021-1420?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.