CVE-2020-7221

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

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