To be clear the flaw was not in Tesla’s software, it was some other third party tool. I don’t know which because a paywall got in the way :)

The software was not named in the article, as it has yet to be patched.

  Colombo provided screenshots and other documents detailing his findings and
  identifying the maker of the affected third-party software, but he asked 
  that Bloomberg not publish specifics because the flaws hadn’t yet been fixed.