Upgrade Symmetricon SyncServer S300 With Latest Firmware

NTP and other UDP-based protocols can be used to amplify denial-of-service attacks.   Servers running the network time protocol (NTP) that use the default unrestricted query configuration are susceptible to a reflected denial-of-service (DRDoS) attack. The Symmetricom SyncServer S300 is susceptible to this vulnerability as it currently do not restrict the NTP query configuration.

Symmetricom released the latest firmware with a feature to turn off/disable the ntp query. 

Here are the steps to upgrade the firmware:

1.    Log in to Web GUI. Go to SYSTEM > Upgrade page.

2.    Click BROWSE... button to select the firmware. Then click UPLOAD button.

3.    Click the firmware inside Current Files window. Then click INSTALL button.
 

4.    Log into CLI via SSH after the upgrade.

5.    Type “ntp_query” and press Enter. This should show “Queries are not restricted and will be responded to”

 

6.    Type “ntp_query disable” and press Enter. Type “Y” to confirm the change.

7.    Log in to Web GUI. Go to NTP > Sysinfo page. Click the RESTART button below.

8.    Log in to CLI. Type “ntp_query” and press Enter. This should show now “Queries are restricted and will not be responded to”