New Delhi: While the Israeli NSO Group-Pegasus snooping via WhatsApp is still fresh in mind, security researchers on Tuesday said they have detected a vulnerability in WhatsApp that led to group chat crash the moment a destructive message was introduced by the hackers in the chat, leading the entire group chat history being deleted forever. Urging all users to immediately update WhatsApp to the latest version, security researchers at global cybersecurity firm Check Point identified the flaw that would allow a bad actor to create a malicious group message to crash Facebook-owned WhatsApp on users' devices.





This is how it works:

To create the malicious message that would impact a WhatsApp group, the bad actor would need to be a member of the target group (WhatsApp allows up to 256 users per group).



From there, the bad actor would need to use WhatsApp Web and their web browser's debugging tool to edit specific message parameters and send the edited text to the group.



This edited message would cause a crash loop for group members, denying users access to all WhatsApp functions until they reinstall WhatsApp and delete the group with the malicious message.



Check Point Research disclosed its findings to the WhatsApp bug bounty programme in August this year. WhatsApp acknowledged the findings and developed a fix to resolve the issue which users should manually apply on their devices. "WhatsApp responded quickly and responsibly to deploy the mitigation against exploitation of this vulnerability," said Vanunu. The Check Point Research team found the vulnerability by inspecting the communications between WhatsApp and WhatsApp Web, the web version of the app which mirrors all messages sent and received from the user's phone. This enabled researchers to see the parameters used for WhatsApp communications and manipulate them.



WhatsApp software engineer Ehren Kret said the company greatly values the work of the technology community to help it maintain strong security for its users globally. "Thanks to the responsible submission from Check Point to our bug bounty programme, we quickly resolved this issue for all WhatsApp apps in mid-September. We have also recently added new controls to prevent people from being added to unwanted groups to avoid communication with untrusted parties all together," Kret said in a statement.



Earlier, the WhatsApp snooping row that involved privacy infringement of 121 Indian users out of 1,400 globally via third-party Israeli Pegasus spyware snowballed into a major political controversy. With the government accusing WhatsApp of not informing it on time and with details that personal data of Indians was compromised by a spyware, a spokesperson for the Facebook-owned instant messaging app had said it regrets that it did not meet the "government's expectations for proactive engagement on these issues."

Since there was no remedy, all members of the group were forced to uninstall and reinstall WhatsApp in order to regain full use. The group chat could not be restored after the crash occurred. The bug has now been fixed. The company issued a fix to resolve the issue which is available since WhatsApp version number 2.19.58."Because WhatsApp is one of the world's leading communication channels for consumers, businesses and government agencies, the ability to stop people using WhatsApp and delete valuable information from group chats is a powerful weapon for bad actors," said Oded Vanunu, Check Point's Head of Product Vulnerability Research. "All WhatsApp users should update to the latest version of the app to protect themselves against this possible attack," Vanunu added.On an average, 65 billion messages are sent on WhatsApp per day by over 1.5 Billion users globally.