Rotem Kerner

**Name of the Vulnerable Software and Affected Versions** Firefox versions prior to 82 **Description** The issue allows an attacker to probe whether an external protocol handler is registered by distinguishing the broken image size of a valid external protocol handler from a non-existent one in an image tag. This can lead to unauthorized access to protected information using a specially crafted image tag. **Recommendations** For Firefox versions prior to 82, update to version 82 or later to resolve the issue. As a temporary workaround, consider restricting the use of external protocol handlers until a patch is applied. Avoid using specially crafted image tags that could exploit this issue until the update is installed.