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A recent change to 1.1.1.1 accidentally altered the order of CNAME records in DNS responses, breaking resolution for some clients. This post explores the technical root cause, examines the source code of affected resolvers, and dives into the inherent ambiguities of the DNS RFCs.
Here we explain how we made our data pipeline scale to 700 million events per second while becoming more resilient than ever before. We share some math behind our approach and some of the designs.
This blog post outlines the root cause analysis and solution for a bug found in Cloudflare’s mTLS implementation
Processor problems have been in the news lately, due to the Meltdown and Spectre vulnerabilities. But generally, engineers writing software assume that computer hardware operates in a reliable, well-understood fashion, and that any problems lie on the software side of the software-hardware divide.
Last week the news of two significant computer bugs was announced. They've been dubbed Meltdown and Spectre and they take advantage of very technical systems that modern CPUs have implemented to make computers extremely fast.
Last Thursday we released details on a bug in Cloudflare's parser impacting our customers. It was an extremely serious bug that caused data flowing through Cloudflare's network to be leaked onto the Internet.
Last Friday, Tavis Ormandy from Google’s Project Zero contacted Cloudflare to report a security problem with our edge servers. He was seeing corrupted web pages being returned by some HTTP requests run through Cloudflare.
At midnight UTC on New Year’s Day, deep inside Cloudflare’s custom RRDNS software, a number went negative when it should always have been, at worst, zero. A little later this negative value caused RRDNS to panic.
We have rolled out automatic protection for all customers for the the newly announced vulnerability called httpoxy.
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.
We keep a close eye on tweets that mention CloudFlare because sometimes we get early warning about odd errors that we are not seeing ourselves through our monitoring systems. Towards the end of August we saw a small number of tweets like this one:
Today there were multiple vulnerabilities released in OpenSSL, a cryptographic library used by CloudFlare (and most sites on the Internet).
On Wednesday of last week, details of the Shellshock bash bug emerged. This bug started a scramble to patch computers, servers, routers, firewalls, and other computing appliances using vulnerable versions of bash.
Below is what we thought as of 12:27pm UTC. To verify our belief we crowd sourced the investigation. It turns out we were wrong. While it takes effort, it is possible to extract private SSL keys.
Today a new vulnerability was announced in OpenSSL 1.0.1 that allows an attacker to reveal up to 64kB of memory to a connected client or server (CVE-2014-0160). We fixed this vulnerability last week before it was made public.
Debugging technical issues online can be tricky. There are many moving pieces; it can be an isolated network connection with the ISP, an issue with your server or one of CloudFlare's data centers could be temporarily having a problem.
