said by TomS_ 
Its a fact that devices as old as these usually are no longer supported by their manufacturer, and this usually means that they stopped releasing firmware updates for them long ago, which means there are likely to be inefficiencies which are resolved with newer hardware/software, bugs which are fixed by newer hardware/software, and vulnerabilities which are fixed by newer software just waiting to be exploited. [/BQUOTE :As long as the modem is not misbehaving, there is no reason to update the firmware, the risk of bricking the device typically outweighs the gains. In some cases, such as Thomson's SpeedTouch DSL modems, the most obvious "benefit" of newer firmwares is more tweaking/diagnostic features getting locked down, not particularly desirable.
As for the vulnerabilities, only two parties have access to your modem's firmware when it is in bridged mode: your carrier and your LAN. If either of those launches an exploit against your modem, you have a more serious issue on your hands than the unlikely modem exploit itself.
