Under certain conditions, when handling a ReadableStream, a race condition can cause a use-after-free. We are aware of targeted attacks in the wild abusing this flaw. This vulnerability affects Thunderbird < 68.7.0, Firefox < 74.0.1, and Firefox ESR < 68.6.1.
Recent assessments:
gwillcox-r7 at November 22, 2020 2:22am UTC reported:
Reported as exploited in the wild as part of Googleβs 2020 0day vulnerability spreadsheet they made available at <https://docs.google.com/spreadsheets/d/1lkNJ0uQwbeC1ZTRrxdtuPLCIl7mlUreoKfSIgajnSyY/edit#gid=1869060786>. Original tweet announcing this spreadsheet with the 2020 findings can be found at <https://twitter.com/maddiestone/status/1329837665378725888>
Assessed Attacker Value: 0
Assessed Attacker Value: 0Assessed Attacker Value: 0