Clubhouse Users’ Raw Audio May Be Exposed to Chinese Partner
A pedestrian wearing a face mask uses a mobile phone in San Francisco. (Photographer: David Paul Morris/Bloomberg)

Clubhouse Users’ Raw Audio May Be Exposed to Chinese Partner

Clubhouse, the popular app that allows people to create digital discussion groups, says it’s reviewing its data security practices after the Stanford Internet Observatory found potential vulnerabilities in its infrastructure that could allow external access to users’ raw audio data.

The SIO confirmed that Agora Inc., a Shanghai-based start-up with offices in Silicon Valley, provides back-end infrastructure to Clubhouse and sells a “real-time voice and video engagement platform.”

User IDs are transmitted in plaintext over the internet, making them “trivial to intercept,” the Observatory noted. User IDs are like a serial number, not the username of the person. Agora would likely have access to users’ raw audio, potentially providing access to the Chinese government, it said.

“Any observer of internet traffic could easily match IDs on shared chatrooms to see who is talking to whom,” the SIO said in its Twitter feed about its findings. “For mainland Chinese users, this is troubling.”

SIO, a program at Stanford University that studies disinformation on the internet and social media platforms, said it observed metadata from a Clubhouse chatroom “being relayed to servers we believe to be hosted in” China. Analysts also saw audio being relayed “to servers managed by Chinese entities and distributed around the world,” their report noted.

SIO said that as a Chinese company, Agora was subject to China’s cybersecurity laws and would be “legally required to assist the government in locating and storing” audio messages authorities said jeopardized national security.

While Agora declined to comment on their relationship with Clubhouse, the company said in a statement it “does not have access to share or store personally identifiable end-user data. Voice or video traffic from non-China based users - including U.S. users - is never routed through China.”

Metadata Transmission

“Any unencrypted data that is transmitted via servers in the PRC (People’s Republic of China) would likely be accessible to the Chinese government,” SIO said in its report. Since SIO was able to observe the transmission of metadata between servers, it believes the Chinese government would be able to collect metadata without having to access Agora’s networks.

However, the Observatory noted that Agora claims not to store user audio or metadata “except to monitor network quality and bill its clients,” which means it wouldn’t have any records of user data if Beijing were to request it.

It also said that as long as audio was stored in the U.S., it was unlikely that the Chinese government would be able to access it.

SIO said it chose to disclose the security issues because they were easy to uncover and because of the risk they pose to Clubhouse’s millions of users. “SIO has discovered other security flaws that we have privately disclosed to Clubhouse and will publicly disclose when they are fixed or after a set deadline.”

Clubhouse’s core software relies on an old version of Agora’s voice library, said Federico Maggi, a senior researcher at Trend Micro.

“By analyzing Clubhouse app we found it includes an outdated release of Agora software library that uses deprecated encryption functions, according to their technical documentation, while security best practice is to always use the latest cryptographic support,” Federico Maggi said in a phone interview.

In addition, that version of Agora library forces data to be sent to China through three specific hardcoded IP addresses even if users are located in Europe or in the U.S, as the Stanford report shows, Maggi added.

Clubhouse Response

In a statement included in the SIO report, Clubhouse said it would roll out changes over 72 hours to add “additional encryption and blocks to prevent Clubhouse clients from ever transmitting pings to Chinese servers. We also plan to engage an external data security firm to review and validate these changes.”

Clubhouse recently raised $100 million at a reported $1 billion valuation, and some of the most notable technology executives, including Tesla Inc.’s Elon Musk, have joined the service.

Agora, known mostly within tech circles as an industrious but low-profile provider of software tools, has soared more than 150% since mid-January. It is now worth almost $11 billion.

In early February users of Clubhouse in China said they were unable to access the app after an explosion of discussions on taboo topics from Taiwan to Xinjiang. Now, it appears that users can access the app by using virtual private networks, one of the few ways people in mainland China can access internet beyond the Great Firewall.

©2021 Bloomberg L.P.

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