Microsoft, Apple and Mozilla among others, trust CNNIC (China Internet Network Information Center) to protect your communications on their platforms by default, regardless of whether or not you are in China. CNNIC has implemented (and tried to mask) internet censorship, produced malware and has very bad security practices. Tech-savvy users in China have been protesting the inclusion of CNNIC as a trusted certificate authority for years. In January 2013, after Github was attacked in China, we publicly called for the the revocation of the trust certificate for CNNIC. In light of the recent spate of man-in-the-middle (MITM) attacks in China, and in an effort to protect user privacy not just in China but everywhere, we again call for revocation of CNNIC Certificate Authority.

Are you vulnerable to CNNIC-issued certificates?

You can test this by visiting the CNNIC site: https://www1.cnnic.cn/gywm/CNNICjs/jj/

If you see a padlock in your browser’s address bar or receive no warning messages, it means that your computer trusts CNNIC as a certificate authority and you might be vulnerable to a MITM attack from CNNIC.

Usernames, passwords, emails, photos, contacts and even financial information can be compromised.

Why is CNNIC not trustworthy?

CNNIC is either complicit in the recent MITM attacks or has intentionally allowed these attacks to happen. We have been witness to the Chinese authorities using MITM attacks against Apple’s iCloud, Google, Microsoft’s Outlook and Yahoo in this month alone.

CNNIC is responsible for the “operation, administration and service organization of national network fundamental resources”. We have evidence that the recent attacks originated from the Chinese internet backbone. Attacks against Yahoo and Google have been implemented on the internet backbone for weeks.

CNNIC is led by the Director of the Bureau of Telecommunications Regulation which is a part of the Ministry of Industry and Information Technology (MIIT). MIIT famously requires all websites hosted in China, from B2B behemoths to blogs, to obtain a license. MIIT regularly scans all websites in China and shuts down any website without a license.

CNNIC-produced malware, titled “Chinese-Language-Surfing Official Edition”, was ranked among the top five instances of malware in 2005 by the Beijing Network Industry Association because of its forced installation and the inability to entirely remove the malware. Microsoft also labeled it as a threat:

BrowserModifier:Win32/CNNIC ..is often installed.. with or without user consent. [It] contains a kernel driver that protects its files and registry settings from being modified or deleted.

via Microsoft Malware Protection Center

Panda Security also noted that CNNIC exploited vulnerabilities and used other malware to distribute the software. CNNIC does this by prompting users to “open files, view malicious web pages, read emails, etc.”. The malware then captures all information entered or saved by the user, which leads to significant privacy issues.

CNNIC and censorship

Public DNS servers operated by CNNIC implement censorship to block users from accessing Facebook, Twitter, YouTube and many other websites. If users in China try to access blocked sites, false DNS responses will be returned. However, if users are located outside of China, DNS responses will be valid.

The screenshot below illustrates that when a China-based user looks up www.twitter.com on the DNS server 1.2.4.8 (This DNS server is operated by CNNIC), they will not be able to connect to the site and will receive a false response, namely 37.61.54.128, which is not owned by Twitter. The user is hence blocked from accessing Twitter.

CNNIC not only implements censorship but also masks its level of involvement. On January 21, 2014, GFW accidentally blocked the entire Internet in China by DNS poisoning top level domains such as .com. We have conclusive evidence that GFW was the cause of the blackout (see our blog post for details). New York Times ran an article entitled “Big Web Crash in China: Experts Suspect Great Firewall” on its front page. CNNIC acknowledged the internet blackout but did not identify the cause of the blackout. CNNIC’s responsibilities in China include Chinese domain name security. As an agency directly responsible for the security of DNS, CNNIC’s failure to investigate such a large-scale and easily identifiable attack can be construed as a coverup for GFW.

One need not look any further than their homepage to see that CNNIC has very bad security practices. The homepage has mixed insecure content. All content indexed on the CNNIC website is HTTP by default (unencrypted), including forms that require user submissions.

Many Chinese users protested when CNNIC was first trusted by Mozilla’s Firefox in 2009. You can read the heated debate on the Mozilla forum. Now that MITM attacks are becoming the new normal on the Chinese Internet, we hope that Mozilla, Microsoft and Apple can revoke trust for CNNIC to protect not just Chinese user data but user data worldwide.

Who trusts CNNIC and what are the consequences of trusting them?

Certificates issued by CNNIC are, by default, trusted by open source products including Mozilla’s Firefox and the Linux distribution Ubuntu, Microsoft’s Windows and Apple’s iOS and OSX. This applies to almost every version of Firefox, Ubuntu and Windows and most models of Apple’s iPhone, even if you have never been to China or you bought your software and hardware outside of China.

CNNIC can issue certificates to intercept encrypted connections without your knowledge.

As evidenced by this screenshot, CNNIC can “ensure the identify of a remote computer”. So if GFW or state-sponsored hackers use CNNIC for an MITM attack, your computer or iPhone will trust a snooped connection hijacked by hackers. Consequently, all your communications can be recorded, analyzed and manipulated by GFW or hackers. Usernames, passwords, text messages, emails, photos, contacts and even financial information can be acquired by the Chinese authorities. Apple has just released Apple Pay - a compromised connection will not only cost you your privacy, it may cost your money as well. iPhones are especially vulnerable to attack because there is no way for iPhone users to view details of a trusted certificate used in the connection. An attack from CNNIC is impossible to identify on iOS. You do not need be in China to be vulnerable to these attacks.

To be fair, man-in-the-middle attacks using CNNIC likely won’t happen on a large scale. Once discovered, CNNIC’s trust certificate would likely be revoked by Mozilla, Microsoft and Apple.

However, highly targeted attacks can go unnoticed. In fact, the large scale attack against Microsoft's Outlook last week “almost went unnoticed”. It took two days for mainstream media to report on the recent iCloud hack.

Why do Mozilla, Microsoft and Apple take such huge risks with their user data, especially considering that Outlook and iCloud have been recently attacked? By trusting CNNIC, these companies continue to put user data in danger not just in China, but everywhere.

What should you do?

First, you can ask Mozilla, Microsoft and Apple to revoke the CNNIC certificate. Tell them that you do not trust CNNIC and ask them to remove it from the system. If you are involved in an open source community such as Mozilla or Linux, ask the community to distrust the certificate and point them to this story. Please also share this article widely and alert users and software vendors to this privacy risk.

Revocation of the CNNIC certificate will take time and the Chinese government will likely exert pressure on companies to keep trusting CNNIC. You can take action yourself and distrust CNNIC by using a free and open source tool to revoke dubious certificate authority in China. This tool was made by Chinese to distrust CNNIC and various certificates used in the MITM attacks against iCloud, Outlook, Yahoo and Google. We recommended that you use the extended version on the Github.

Once you used the tool, you should see a red warning bar when accessing https://www1.cnnic.cn/gywm/CNNICjs/jj/. This means that your device no longer trusts CNNIC and hence the Chinese authorities can no longer tamper with your connection.