A data leak is the unintended exposure of data, for example through a misconfigured database or an unprotected storage bucket.
Unlike a targeted break-in, the data usually lies open by mistake until someone finds it.
Causes of Data Leaks
Data leaks almost always arise from mistakes, not sophisticated attacks.
Human Error
Misaddressed emails, publicly shared links and data on private devices or in test systems are typical causes.
Credentials in published source code also lead to leaks.
System Vulnerabilities
Cloud storage without a password, open database ports, faulty access rights and unpatched software make data reachable for anyone.
Automated scanners find such gaps within hours.
Consequences of Data Leaks
Exposed data is often collected and resold.
For Individuals
Those affected receive more phishing emails and risk identity theft and account takeovers.
Leaked passwords are used for attacks on other services.
For Organizations
Companies face fines, damages and loss of trust.
Trade secrets can fall into the wrong hands.
Prevention of Data Leaks
Data leaks can largely be avoided with simple, consistent measures.
Technical Measures
Encryption, need-to-know access rights, secure defaults, regular checks for exposed services and data loss prevention (DLP) tools protect data.
Secret keys never belong in source code.
Organizational Policies
Rules on data classification, file sharing and data minimisation define what may go where.
Data no longer needed should be deleted.
User Education
Staff should know how to share files securely and which data needs special protection.
Mistakes should be reportable without fear.
Conclusion
Data leaks usually result from avoidable mistakes.
Secure defaults, clear rules and regular checks keep data where it belongs.