If you're using an older Linksys E-series router and have trouble finding a firmware upgrade, you may have to wait a few weeks. In the search box under "Start Here," type the model number of your router.You can find the model number on the underside of your router.The model number should auto-complete when you start to type it into the Web page.Click on that auto-completed name and you'll be taken directly to the support page for your router. On the router model's support page, select "Downloads" from the row of tabs near the middle of the screen.The download page where Linksys used to provide their TFTP client has been reported down for a long time, but you can still grab the download from Archive.org's Wayback Machine.Visit this link and then download the utility mentioned on that page.Click "Continue" on that popup to complete the process. Congratulations &mash; you're now running the latest firmware for your router.There are a few extra steps you should take to make sure your router is as secure as possible. In the router's Web-based setup page, click on the "Administration" tab at the top.
The client displays status and error messages as would appear on the command line, and the client even works with other TFTP capable routers apart from Linksys ones.
A new worm, or piece of self-replicating malware, nicknamed "The Moon" has been infecting Linksys E-series routers, and possibly some Linksys Wireless-N-series routers, by exploiting a vulnerability in the way the routers verify administrator access.