Security researchers have uncovered multiple vulnerabilities in various tunneling protocols, allowing threat actors to launch DoS attacks. Millions of VPN servers, home routers, and internet hosts could be affected, with a significant number of vulnerable endpoints located in China. The vulnerabilities were found in tunneling protocols like IPIP/IP6IP6, GRE/GRE6, 4in6, and 6in4, posing risks to data transmission security. Experts warn of potential anonymous attacks and breaches into private networks due to misconfigured systems accepting tunneling packets without proper verification. The discovery points to the need for enhanced cybersecurity measures to protect against exploitation of these vulnerabilities.