Security Experts:

Apple to Revoke Trust in WoSign Certificates

After Mozilla announced that it might ban new certificates issued by Chinese certificate authority (CA) WoSign and its subsidiary StartCom for at least one year, Apple has decided to take measures.

The tech giant informed customers on Friday that it will soon release security updates to revoke trust in the WoSign CA Free SSL Certificate G2 intermediate CA in iOS and OS X, blaming the decision on “multiple control failures in their certificate issuance processes.”

The company pointed out that WoSign root certificates are not in the iOS or macOS trust stores, but the intermediate CA used its ties to StartCom and Comodo to acquire trust in Apple products.

Existing certificates that have been added to Certificate Transparency logs until September 19 will continue to be trusted until they expire or get revoked. However, Apple could at any time decide to untrust certificates from this intermediate CA.

“As the investigation progresses, we will take further action on WoSign/StartCom trust anchors in Apple products as needed to protect users,” Apple said.

Following an investigation, Mozilla published a report detailing more than a dozen incidents involving WoSign. The Firefox developer is displeased that WoSign issued SHA-1 certificates after the January 1, 2016, deadline and backdated them so that they would still be accepted by web browsers.

Mozilla also pointed to some bugs that allowed applicants to add extra arbitrary domains to a certificate – this was exploited by an expert to show that he could obtain SSL certificates for GitHub.com. Another problem is that CAs must inform Mozilla if their ownership changes, but StartCom failed to inform the organization that it had been acquired by WoSign.

Due to these issues, some Mozilla representatives proposed that new certificates from WoSign and StartCom be banned for at least one year. The penalty for the CAs is still being discussed, but a decision is expected to be announced after a face-to-face meeting on Tuesday between representatives of Mozilla, StartCom and Qihoo 360, WoSign's largest shareholder.

Google and Microsoft have yet to announce if they plan on taking any action against WoSign and StartCom.

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Eduard Kovacs (@EduardKovacs) is a contributing editor at SecurityWeek. He worked as a high school IT teacher for two years before starting a career in journalism as Softpedia’s security news reporter. Eduard holds a bachelor’s degree in industrial informatics and a master’s degree in computer techniques applied in electrical engineering.