WhatsApp has finally fixed a bug in its "View Once" privacy feature that allowed malicious users to save pictures and videos that were supposed to be viewed only once and then vanish. The bug, which was reported by TechCrunch in September, affected the browser-based web app and allowed users to display and keep the media sent as "View Once."

The "View Once" feature, launched in 2021, is designed to prevent recipients from saving, sharing, forwarding, copying, and even screenshotting or screen recording media sent as "View Once." However, the bug in the implementation of the feature allowed users to circumvent this protection. According to security researcher Tal Be'ery, who alerted WhatsApp and TechCrunch of the bug, there were also several browser extensions and social media posts that advertised easy solutions to circumvent the privacy feature, allowing users to install an extension and automatically be able to display and save media sent as "View Once."

A WhatsApp spokesperson, Zade Alsawah, confirmed that the company has rolled out a longer-term fix that resolves the issue. "We're constantly building in layers of privacy protection, and that includes rolling out key updates to view once on web," Alsawah said in an email. "As always, we continue to encourage users to only send View Once messages to people they know and trust, and make sure they're on the latest version of the app."

After WhatsApp's fix, users of those browser extensions, some of which require a paid subscription, are complaining that they don't work anymore. In a test performed by TechCrunch on Friday, when we received a View Once Message on WhatsApp's web app, the app displayed the usual warning message, indicating that the fix is in place.

Be'ery, who is the CTO and co-founder of crypto wallet Zengo, published a blog post on Monday analyzing the fix. He expressed satisfaction that WhatsApp has finally resolved the issue, saying, "Sometimes, when a vulnerability is exploited in the wild, a responsible disclosure is to go public. We are very happy that our research and publication drove WhatsApp to fix the issue and protect the privacy of their users."

The "View Once" feature is designed to work only on WhatsApp's iOS and Android apps, and not on the web or desktop app. The bug fix is a significant step towards ensuring the privacy and security of WhatsApp users, especially in light of the growing concerns around online privacy and data protection.

The incident highlights the importance of responsible disclosure of vulnerabilities and the need for tech companies to prioritize user privacy and security. It also underscores the ongoing efforts of security researchers and tech journalists to hold companies accountable for protecting their users' data.