What's your longest-lasting bug that you created or encountered?

What's the bug that you inadvertently 开发者_JAVA技巧created or encountered that remained undiscovered for the longest period of time?

How about this vulnerability that was left unpatched for 17 years: http://www.geek.com/articles/chips/17-year-old-unpatched-windows-vulnerability-discovered-20100120/

There was also the "drag-and-drop" vulnerability that allowed for remote code execution in IE that was being exploited for many years before it was finely patched. There is also the "Passing The Hash" SMB vulnerability that Microsoft ignored from ~2000-2007. In both cases Microsoft denied that there was a vulnerability while hackers happy to pw3n the neglected windows boxen.

All three of these are now patched.

Related:

• The First Computer Bug!
• History's Worst Software Bugs
• 20 Famous Software Disasters