TikTok fixes security flaw that exposed private user data

(Image credit: TikTok)

UPDATE: TikTok's parent company ByteDance says it has now fixed the vulnerability following Check Point's release.

"The security and privacy of the TikTok community is our highest priority, and we appreciate the work of trusted partners like Check Point in identifying potential issues so that we can resolve them before they affect users," a TikTok spokesperson told BleepingComputer.

"We continue to strengthen our defenses, both by constantly upgrading our internal capabilities such as investing in automation defenses, and also by working with third parties."

ORIGINAL STORY: Investigators at cybersecurity firm Check Point Research have discovered a vulnerability affecting the popular video-sharing platform TikTok that allowed threat actors to steal users’ private data. 

The flaw, which has since been patched, raises questions about how much data users can safely share with mobile apps.

The security flaw was identified residing within TikTok “Find Friends” feature and enabled attackers to access some of the user’s profile details, including their phone number, TikTok nickname, profile and avatar pictures, unique user IDs, and certain profile settings.

Be careful what you share

Detailing the methodology employed to exploit the vulnerability, Check Point explained that TikTok employs contact syncing to help individuals find other users that they may know. However, it was found that attackers could manipulate the sign-in process, allowing them to upload and sync contacts at scale, letting them build up a database of users and phone numbers that could be used for follow-up attacks.

After being informed of the vulnerability, TikTok developer ByteDance quickly issued a patch, making the app safe to use once more.

“Our primary motivation was to explore the privacy of TikTok,” Oded Vanunu, Head of Products Vulnerabilities Research at Check Point, said. “We were curious to see if the TikTok platform could be used to gain access to private user data.  We were able to bypass multiple protection mechanisms of TikTok that led to privacy violation. The vulnerability could have allowed an attacker to build a database of user details and their respective phone numbers. An attacker with that degree of sensitive information could perform a range of malicious activities, such as spear phishing or other criminal actions.”

However, this is not the first time that a security flaw has been found affecting TikTok. A year ago, Check Point published a research paper on another set of vulnerabilities. Ultimately, the best practice that users can take, with any app, is to only share as little information as possible.

Barclay Ballard

Barclay has been writing about technology for a decade, starting out as a freelancer with ITProPortal covering everything from London’s start-up scene to comparisons of the best cloud storage services.  After that, he spent some time as the managing editor of an online outlet focusing on cloud computing, furthering his interest in virtualization, Big Data, and the Internet of Things.