mysql_install_db in MariaDB 10.4.7 through 10.4.11 allows privilege escalation from the mysql user account to root because chown and chmod are performed unsafely, as demonstrated by a symlink attack on a chmod 04755 of auth_pam_tool_dir/auth_pam_tool. NOTE: this does not affect the Oracle MySQL product, which implements mysql_install_db differently.
Weakness
The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Mariadb | Mariadb | 10.4.7 (including) | 10.4.11 (including) |
| Mariadb-10.0 | Ubuntu | esm-apps/xenial | * |
| Mariadb-10.0 | Ubuntu | xenial | * |
| Mariadb-5.5 | Ubuntu | trusty | * |
| Mysql-5.5 | Ubuntu | esm-infra-legacy/trusty | * |
| Mysql-5.5 | Ubuntu | precise/esm | * |
| Mysql-5.5 | Ubuntu | trusty | * |
| Mysql-5.5 | Ubuntu | trusty/esm | * |
| Mysql-5.6 | Ubuntu | trusty | * |
| Percona-xtradb-cluster-5.5 | Ubuntu | trusty | * |
Potential Mitigations
- Follow the principle of least privilege when assigning access rights to entities in a software system.
- Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/132.html
- https://cwe.mitre.org/data/definitions/17.html
- https://cwe.mitre.org/data/definitions/35.html
- https://cwe.mitre.org/data/definitions/76.html
References
- https://bugzilla.suse.com/show_bug.cgi?id=1160868
- https://github.com/MariaDB/server/commit/9d18b6246755472c8324bf3e20e234e08ac45618
- https://seclists.org/oss-sec/2020/q1/55
- https://bugzilla.suse.com/show_bug.cgi?id=1160868
- https://github.com/MariaDB/server/commit/9d18b6246755472c8324bf3e20e234e08ac45618
- https://seclists.org/oss-sec/2020/q1/55