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March 04, 2016 6:02 PM
A Deep Dive Into DNS Packet Sizes: Why Smaller Packet Sizes Keep The Internet Safe
One way that attackers DDoS websites is by repeatedly doing DNS lookups that have small queries, but large answers. The attackers spoof their IP address so that the DNS answers are sent to the server they are attacking, this is called a reflection attack....
February 29, 2016 1:42 PM
A tale of a DNS exploit: CVE-2015-7547
A buffer overflow error in GNU libc DNS stub resolver code was announced last week as CVE-2015-7547. While it doesn't have any nickname yet (last year's Ghost was more catchy), it is potentially disastrous....
January 19, 2016 6:19 PM
Go coverage with external tests
The Go test coverage implementation is quite ingenious: when asked to, the Go compiler will preprocess the source so that when each code portion is executed a bit is set in a coverage bitmap....
January 13, 2016 11:44 AM
Flexible, secure SSH with DNSSEC
If you read this blog on a regular basis, you probably use the little tool called SSH, especially its ubiquitous and most popular implementation OpenSSH....
November 10, 2015 1:56 PM
Announcing Universal DNSSEC: Secure DNS for Every Domain
CloudFlare launched just five years ago with the goal of building a better Internet. That’s why we are excited to announce that beginning today, anyone on CloudFlare can secure their traffic with DNSSEC in just one simple step....
October 29, 2015 9:26 PM
Creative foot-shooting with Go RWMutex
Hi, I'm Filippo and today I managed to surprise myself! (And not in a good way.)
I'm developing a new module ("filter" as we call them) for RRDNS, CloudFlare's Go DNS server. ...
October 20, 2015 8:54 PM
DNSSEC is Open for Beta
Since January, CloudFlare has been running a small, private beta for DNSSEC. Starting today, the DNSSEC beta is open for everyone. ...
September 25, 2015 4:01 PM
Mobile Ad Networks as DDoS Vectors: A Case Study
CloudFlare servers are constantly being targeted by DDoS'es. We see everything from attempted DNS reflection attacks to L7 HTTP floods involving large botnets....
August 06, 2015 1:40 PM
DNS parser, meet Go fuzzer
Here at CloudFlare we are heavy users of the github.com/miekg/dns Go DNS library and we make sure to contribute to its development as much as possible. Therefore when Dmitry Vyukov published go-fuzz and started to uncover tens of bugs in the Go standard library, our task was clea...
August 04, 2015 10:36 AM
A deep look at CVE-2015-5477 and how CloudFlare Virtual DNS customers are protected
Last week ISC published a patch for a critical remotely exploitable vulnerability in the BIND9 DNS server capable of causing a crash with a single packet.
...
August 03, 2015 11:26 AM
Quick and dirty annotations for Go stack traces
CloudFlare’s DNS server, RRDNS, is entirely written in Go and typically runs tens of thousands goroutines. Since goroutines are cheap and Go I/O is blocking we run one goroutine per file descriptor we listen on and queue new packets for processing....
July 06, 2015 9:30 PM
The Internet is a cooperative system: CNAME to Dyn DNS outage of 6 July 2015
Today, shortly after 21:00 UTC, on our internal operations chat there was a scary message from one of our senior support staff: "getting DNS resolution errors on support.cloudflare.com", at the same time as automated monitoring indicated a problem....
July 03, 2015 1:41 PM
Blue Light Special: Ensuring fast global configuration changes
CloudFlare operates a huge global network of servers that proxy our customers' web sites, operate as caches, inspect requests to ensure they are not malicious, deflect DDoS attacks and handle one of the largest authoritative DNS systems in the world. ...
June 24, 2015 4:40 PM
Check out these brand new videos on how to optimize CloudFlare
Someone once said that the best things in life are free and I can’t agree more. I want to draw the attention of the CloudFlare community to a great resource that helps maximize the value of our product. ...