CVE-2021-27770: Hcltech Sametime

High severity, CVSS 8.8. EPSS: 0.7% chance of exploitation in the next 30 days.

The vulnerability was discovered within the “FaviconService”. The service takes a base64-encoded URL which is then requested by the webserver. We assume this service is used by the “meetings”-function where users can specify an external URL where the online meeting will take place.

Affected products

• Hcltech Sametime: version 11.6 only

Published 2022-05-12. Last modified 2026-06-17.