CVE-2021-3017

This is embarrassingly simple: on these Intelbras routers, the Wi-Fi password sits in plaintext in the web interface's HTML source, in a variable called def_wirelesspassword. Anyone who can reach the admin page and hit View Source reads the wireless credential directly — no exploit, no tooling, just the browser. The scope is limited to confidentiality (the password), but for a home or small-office router that credential is the whole perimeter.

The practical urgency depends entirely on who can reach that web interface. If the management page is only on the LAN, an attacker already needs a foothold on the network to read a password protecting that same network — modest value. The danger spikes if remote management is enabled and the interface faces the internet, because then the wireless key is effectively public to any scanner that fingerprints these devices. Consumer routers are notorious for shipping remote admin on or getting exposed by accident.

For us the entire decision is reachability. We'd inventory any Intelbras WIN 300 or WRN 342 in the estate and check one thing: is the web interface exposed beyond the local segment? An internet-facing one is a live credential leak and gets pulled or firewalled now; a LAN-only one is a hygiene item. There's no version ceiling to chase here — the data cites devices through 2021-01-04 — so mitigation is exposure control, not patching.