A service worker can send the activate event on itself periodically which allows it to run perpetually, allowing it to monitor activity by users. Affects all versions prior to Firefox 60.
openSUSE Leap 15.0 openSUSE Leap 15.3 openSUSE Leap 15.4 openSUSE Leap 42.3 openSUSE Tumbleweed SUSE Linux Enterprise Desktop 12 SP4 SUSE Linux Enterprise Desktop 12 SP5 SUSE Linux Enterprise High Performance Computing 12 SP2 SUSE Linux Enterprise High Performance Computing 15 SUSE Linux Enterprise Point of Sale 12 SP2-CLIENT SUSE Linux Enterprise Server 12 SP1-LTSS SUSE Linux Enterprise Server 12 SP2 SUSE Linux Enterprise Server 12 SP2-BCL SUSE Linux Enterprise Server 12 SP2-ESPOS SUSE Linux Enterprise Server 12 SP2-LTSS SUSE Linux Enterprise Server 12 SP3 SUSE Linux Enterprise Server 12 SP3-BCL SUSE Linux Enterprise Server 12 SP3-ESPOS SUSE Linux Enterprise Server 12 SP3-LTSS SUSE Linux Enterprise Server 12 SP3-TERADATA SUSE Linux Enterprise Server 12 SP4 SUSE Linux Enterprise Server 12 SP5 SUSE Linux Enterprise Server 15 SUSE Linux Enterprise Server for SAP Applications 12 SP1 SUSE Linux Enterprise Server for SAP Applications 12 SP1-LTSS SUSE Linux Enterprise Server for SAP Applications 12 SP2 SUSE Linux Enterprise Server for SAP Applications 12 SP2-BCL SUSE Linux Enterprise Server for SAP Applications 12 SP2-ESPOS SUSE Linux Enterprise Server for SAP Applications 12 SP2-LTSS SUSE Linux Enterprise Server for SAP Applications 12 SP3 SUSE Linux Enterprise Server for SAP Applications 12 SP3-BCL SUSE Linux Enterprise Server for SAP Applications 12 SP3-ESPOS SUSE Linux Enterprise Server for SAP Applications 12 SP3-LTSS SUSE Linux Enterprise Server for SAP Applications 12 SP3-TERADATA SUSE Linux Enterprise Server for SAP Applications 12 SP4 SUSE Linux Enterprise Server for SAP Applications 12 SP5 SUSE Linux Enterprise Server for SAP Applications 15 SUSE Linux Enterprise Software Development Kit 12 SP4 SUSE Linux Enterprise Software Development Kit 12 SP5 SUSE OpenStack Cloud 7 SUSE OpenStack Cloud 8 SUSE OpenStack Cloud Crowbar 8 SUSE Package Hub for SUSE Linux Enterprise 12 SP2 SUSE Package Hub for SUSE Linux Enterprise 15