Weak security

Start here: https://support.apple.com/en-us/HT202068

About privacy and security warnings

If your Apple device shows a privacy warning or weak-security warning about a Wi-Fi network, that network could expose information about your device. Apple recommends connecting to Wi-Fi networks that meet or exceed the security standards.

Router settings

To ensure that your devices can connect securely and reliably to your network, apply these settings consistently to each Wi-Fi router and access point, and to each band of a dual-band, tri-band, or other multiband router.

Security

 Set to WPA3 Personal for better security

      Set to WPA2/WPA3 Transitional for compatibility with older devices

The security setting defines the type of authentication and encryption used by your router, and the level of privacy protection for data transmitted over its network. Whichever setting you choose, always set a strong password for joining the network.

• WPA3 Personal is the newest, most secure protocol currently available for Wi-Fi devices. It works with all devices that support Wi-Fi 6 (802.11ax), and some older devices. 
• WPA2/WPA3 Transitional is a mixed mode that uses WPA3 Personal with devices that support that protocol, while allowing older devices to use WPA2 Personal (AES) instead.
• WPA2 Personal (AES) is appropriate when you can't use one of the more secure modes. In that case, also choose AES as the encryption or cipher type, if available.

Weak security settings to avoid on your router

Don't create or join networks that use older, deprecated security protocols. These are no longer secure, they reduce network reliability and performance, and they cause your device to show a security warning:

• WPA/WPA2 mixed modes
• WPA Personal
• WEP, including WEP Open, WEP Shared, WEP Transitional Security Network, or Dynamic WEP (WEP with 802.1X)
• TKIP, including any security setting with TKIP in the name

Settings that turn off security, such as None, Open, or Unsecured, are also strongly discouraged. Turning off security disables authentication and encryption and allows anyone to join your network, access its shared resources (including printers, computers, and smart devices), use your internet connection, and monitor the websites you visit and other data transmitted over your network or internet connection. This is a risk even if security is turned off temporarily or for a guest network.

Network name (SSID)

 Set to a single, unique name (case-sensitive)

The Wi-Fi network name, or SSID (service set identifier), is the name your network uses to advertise its presence to other devices. It's also the name that nearby users see on their device's list of available networks.

Use a name that's unique to your network, and make sure that all routers on your network use the same name for every band they support. For example, don't use common names or default names such as linksys, netgear, dlink, wireless, or 2wire, and don't give your 2.4GHz and 5GHz bands different names.

If you don't follow this guidance, devices might not connect reliably to your network, to all routers on your network, or to all available bands of your routers. And devices that join your network are more likely to encounter other networks that have the same name, and then automatically try to connect to them.