A Time-of-Check Time-of-Use bug existed in the Maintenance (Updater) Service that could be abused to grant Users write access to an arbitrary directory. This could have been used to escalate to SYSTEM access.This bug only affects Firefox on Windows. Other operating systems are unaffected.. This vulnerability affects Firefox < 97, Thunderbird < 91.6, and Firefox ESR < 91.6.
The product checks the state of a resource before using that resource, but the resource’s state can change between the check and the use in a way that invalidates the results of the check. This can cause the product to perform invalid actions when the resource is in an unexpected state.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Firefox | Mozilla | * | 97.0 (excluding) |
| Firefox_esr | Mozilla | * | 91.6 (excluding) |
| Thunderbird | Mozilla | * | 91.6 (excluding) |