Alibaba-owned UCWeb accused of leaking user information

"Chinese and English-language versions of the browser made easily available to third parties personally identifiable information"

Citizen Lab, based at the University of Toronto, said UC Browser had more than 500 million registered users and was the most popular web browser in China and India.

A Canadian technology research group on Thursday said UC Browser, a popular mobile web browser of Alibaba Group Holding Ltd., paid more than $1 billion for leaking sensitive user data.

Citizen Lab said the Chinese and English-language versions of the Browser, developed by UCWeb Inc., made easily available to third parties personally identifiable information like location, search details and mobile subscriber and device numbers.

The transmission of this information "represents a privacy risk for users because it allows anyone with access to the data traffic to identify users and their devices, and collect their private search data", it said in a report.

A spokesman of UCWeb declined to comment.

Citizen Lab, based at the University of Toronto, said UC Browser had more than 500 million registered users and was the most popular web browser in China and India.

Citizen Lab said the Chinese version more vulnerable and said that by installing and opening those version users exposed "a significant number" of personal identifiers and location information to third parties.

"By leaking a large volume of fine-grained data points to multiple network operators, the UC Browser app is increasing the risks to its users that such data may be used against them by authorities, criminals, or other third parties," it said.

Alibaba fully acquired UCWeb last June, in what was at the time the biggest merger in Chinese internet history.