If a malicious attacker has used another vulnerability to gain full control over a content process, they may be able to replace the alternate data resources stored in the JavaScript Start-up Bytecode Cache (JSBC) for other JavaScript code. If the parent process then runs this replaced code, the executed script would be run with the parent process privileges, escaping the sandbox on content processes. This vulnerability affects Firefox < 60.
The product does not preserve permissions or incorrectly preserves permissions when copying, restoring, or sharing objects, which can cause them to have less restrictive permissions than intended.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Ubuntu_linux | Canonical | 14.04 (including) | 14.04 (including) |
| Ubuntu_linux | Canonical | 16.04 (including) | 16.04 (including) |
| Ubuntu_linux | Canonical | 17.10 (including) | 17.10 (including) |
| Ubuntu_linux | Canonical | 18.04 (including) | 18.04 (including) |
| Firefox | Ubuntu | artful | * |
| Firefox | Ubuntu | bionic | * |
| Firefox | Ubuntu | devel | * |
| Firefox | Ubuntu | trusty | * |
| Firefox | Ubuntu | upstream | * |
| Firefox | Ubuntu | xenial | * |