When following the value's prototype chain, it was possible to retain a reference to a locale, delete it, and subsequently reference it. This resulted in a use-after-free and a potentially exploitable crash. This vulnerability affects Firefox < 70, Thunderbird < 68.2, and Firefox ESR < 68.2.
| Software | From | Fixed in |
|---|---|---|
| mozilla / firefox_esr | - | 68.2 |
| mozilla / thunderbird | - | 68.2 |
| mozilla / firefox | - | 70.0 |
| canonical / ubuntu_linux | 16.04 | 16.04.x |