Companies House has suspended its online filing service after a critical glitch exposed directors' personal information to the public. The UK's official corporate registry discovered that a bug allowed anyone to view and potentially modify sensitive details including addresses, email addresses, and full dates of birth for over 5 million companies registered in the UK.

This security flaw affected major corporations like AstraZeneca, Shell, and Tesco, whose directors' information became accessible through a simple browser navigation trick. By entering a company number and repeatedly pressing the back button, users could access restricted filing systems and potentially upload fraudulent documents. The vulnerability was discovered by Dan Neidle of Tax Policy Associates.

Companies House has closed the affected WebFiling service while investigating the breach. The registry apologized for the inconvenience but must now determine how long the flaw existed and what data may have been compromised. This incident raises serious questions about the security of corporate registration systems and the potential for fraud targeting business leaders.