Submitted via IRC for SoyCow1937
One day after the CAA (Certificate Authority Authorization) standard became obligatory on September 8, a German security researcher caught Comodo breaking the rules and issuing an SSL certificate it was not supposed to issue.
CAA allows website owners to specify what Certificate Authorities (CAs) are allowed to issue certificates in their name. Site owners can set up a CAA rule for their domain by adding a text field in DNS entries such as the one below:
bleepingcomputer.com. CAA 0 issue "symantec.com"
This small rule tells any Certificate Authority that only Symantec can issue SSL certificates for the BleepingComputer.com domain.
According to the rules of the CAA standard approved by the CA/Browser Forum in Ballot 187, this April, Certificate Authorities such as Comodo have to check a CAA field in DNS records before issuing new SSL certificates.
On Monday, German security researcher Hanno Böck shared with the infosec community that he managed to obtain an SSL certificate from Comodo — now revoked — for his own website, even if the CAA field limited SSL issuance only to Let's Encrypt.
(Score: 3, Informative) by NCommander on Wednesday September 13 2017, @03:06PM
Not disagreeing with DNS security is a joke unless you're DNSSEC signed.
We are here at soylentnews.org (and at sylnt.us), and we publish CAA records, but I have no solid belief that they're really going to stop a misissue. The only things that can protect us from a misissue is HPKP which for various reasons we've been hestistant to deploy, or CT-transparency+OSCP-Must-Staple.
Still always moving