In previous blog post we discussed how we use the TPROXY iptables module to power Cloudflare Spectrum. With TPROXY we solved a major technical issue on the server side, and we thought we might find another use for it on the client side of our product.
Abusing Linux's firewall: the hack that allowed us to build Spectrum
Introducing Spectrum: a new Cloudflare feature that brings DDoS protection, load balancing, and content acceleration to any TCP-based protocol.Today we are releasing Spectrum.
eBPF, Sockets, Hop Distance and manually writing eBPF assembly
A friend gave me an interesting task: extract IP TTL values from TCP connections established by a userspace program. This seemingly simple task quickly exploded into an epic Linux system programming hack.
The real cause of large DDoS - IP Spoofing
A week ago we published a story about new amplification attacks using memcached protocol on UDP port 11211. A few things happened since then: Github announced it was a target of 1.3Tbps memcached attack. OVH and Arbor reported similar large attacks with the peak reported at 1.7Tbps.
Memcrashed - Major amplification attacks from UDP port 11211
Over last couple of days we've seen a big increase in an obscure amplification attack vector - using the memcached protocol, coming from UDP port 11211. In the past, we have talked a lot about amplification attacks happening on the internet.