Andrew Nacin, lead developer of WordPress, just finished a talk at Loopconf, where he talked about a series of related WordPress security fixes that spanned two years, with the final fix included into WordPress core under the guise of Emoji support.
The code has been in trunk since January, months before the release of 4.2. But it was there under the guise of Emoji support, as “noone had any idea what it did because it was 1,000 lines of the database abstraction layer to just remove invalid characters.”
Because of how opaque the vulnerability and the corresponding fix were, the team was able to spend a very long time working on and fixing the issue, all without exposing the vulnerability to the general public.
Beautiful. (via ma.tt)