Apport creates a world writable lock file with root ownership in the world writable /var/lock/apport directory. If the apport/ directory does not exist (this is not uncommon as /var/lock is a tmpfs), it will create the directory, otherwise it will simply continue execution using the existing directory. This allows for a symlink attack if an attacker were to create a symlink at /var/lock/apport, changing apports lock file location. This file could then be used to escalate privileges, for example. Fixed in versions 2.20.1-0ubuntu2.23, 2.20.9-0ubuntu7.14, 2.20.11-0ubuntu8.8 and 2.20.11-0ubuntu22.
Weakness
The product creates a temporary file in a directory whose permissions allow unintended actors to determine the file’s existence or otherwise access that file.
Affected Software
| 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 | 18.04 (including) | 18.04 (including) |
| Ubuntu_linux | Canonical | 19.10 (including) | 19.10 (including) |
| Apport | Ubuntu | bionic | * |
| Apport | Ubuntu | devel | * |
| Apport | Ubuntu | eoan | * |
| Apport | Ubuntu | esm-infra-legacy/trusty | * |
| Apport | Ubuntu | esm-infra/bionic | * |
| Apport | Ubuntu | esm-infra/focal | * |
| Apport | Ubuntu | esm-infra/xenial | * |
| Apport | Ubuntu | focal | * |
| Apport | Ubuntu | trusty | * |
| Apport | Ubuntu | trusty/esm | * |
| Apport | Ubuntu | xenial | * |