Most everyone in the tech space has been living in interesting times, but this week isn't done yet, and it's already quite special for systems administrators worldwide. They already had to deal with the critical PHP RCE vulnerability, but they also have to update untold amounts of machines and software, thanks to eight insecure intermediate CA certificates that can allow attackers to impersonate any domain and/or pretend their malware is from a legitimate source.

An attacker anywhere in the path of your network traffic, like, say, in a company or government network, public Wi-Fi, your ISP, or one of any number of government entities, can intercept your connection and pretend that they're any website, like apple.com, amazon.com, or bankofamerica.com. If not updated, your operating system and installed software would be none the wiser. Additionally, with the code signing certificates, an application you download can be shown as completely legitimate from, say, Microsoft or Google.

The way that software checks a certificate is legitimate is by verifying its "chain." For example, a website like tomshardware.com has a certificate, issued and signed by an intermediate Certification Authority (or CA, a certificate-selling company), and whose certificate, in turn, is trusted and signed by root certificates — whose exceedingly precious keys are kept offline in safes. In this week's event, Indian CA firm eMudhra issued six TLS and two code-signing intermediate certificates with easily guessable keys.

Your operating system and potentially tens of different applications on your machine all keep a list of which root certificates and CAs are trusted.

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