An issue was discovered on NETGEAR R8500, R8300, R7000, R6400, R7300, R7100LG, R6300v2, WNDR3400v3, WNR3500Lv2, R6250, R6700, R6900, and R8000 devices. They are prone to password disclosure via simple crafted requests to the web management server. The bug is exploitable remotely if the remote management option is set, and can also be exploited given access to the router over LAN or WLAN. When trying to access the web panel, a user is asked to authenticate; if the authentication is canceled and password recovery is not enabled, the user is redirected to a page that exposes a password recovery token. If a user supplies the correct token to the page /passwordrecovered.cgi?id=TOKEN (and password recovery is not enabled), they will receive the admin password for the router. If password recovery is set the exploit will fail, as it will ask the user for the recovery questions that were previously set when enabling that feature. This is persistent (even after disabling the recovery option, the exploit will fail) because the router will ask for the security questions.

References

• https://nvd.nist.gov/vuln/detail/CVE-2017-5521
• https://www.exploit-db.com/exploits/41205/
• http://kb.netgear.com/30632/Web-GUI-Password-Recovery-and-Exposure-Security-Vulnerability
• http://www.securityfocus.com/bid/95457