TYPO3 Core

When you have backend debugging enabled and e.g. make an db insert with huge amount of data and it fails, the database connection class will trigger the (TYPO3\CMS\Core\Utility\DebugUtility::)debug to visualize the stack trace within the backend.

Because the debug message will be rendered by javascript, the message must be encoded by the javascriptencoder (\TYPO3\CMS\Core\Encoder\JavaScriptEncoder) encode function. The javscript encoder use the character convert service to fetch character for character for encoding, which lame for at all 23100 characters i had. So i went into a max_execution_timeout after 600 seconds (10 minutes).

So i've written some test to reproduce this issue. On line 89 within the javascript encoder class, the debug string will be split into characters via the charsetconverter service, i already said. This next 4 lines cause a duration of over 10 minutes with a 23000 character long string. I've also tested it with an random 1000 character long string and it had already a duration of 9 seconds. Maybe we need a limitation for strings to prevent running into timeouts.