CVE-2019-14899 and mitigation

Installing and Using OpenWrt Network and Wireless Configuration
1

I would like to ask for a practical solution for vulnerability CVE-2019-14899:

A vulnerability was discovered in Linux, FreeBSD, OpenBSD, MacOS, iOS, and Android that allows a malicious access point, or an adjacent user, to determine if a connected user is using a VPN, make positive inferences about the websites they are visiting, and determine the correct sequence and acknowledgement numbers in use, allowing the bad actor to inject data into the TCP stream. This provides everything that is needed for an attacker to hijack active connections inside the VPN tunnel.

I am running WireGuard on my OpenWrt router and do not want to be susceptible to security threats. The three solutions which were given were:

  1. Turn on reverse path filtering
  2. Turn on bogon filtering
  3. Only allow packets of the same size

Right now, I have added

net.ipv4.conf.all.rp_filter = 1
net.ipv4.conf.default.rp_filter = 1

to my sysctl.conf file, I just have no way to test or be confirmed that this is the solution. Does anyone have any information on this subject?

2

the vulnerability is only impacting Linux and Unix systems and requires that the attacker has control over your Internet access point and can therefore reach and affect your computer outside of the VPN

If your AP is compromised, changing the kernel settings will not do much good.

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