CVE-2016-6662
Description
It was discovered that the MySQL logging functionality allowed writing to MySQL configuration files. An administrative database user, or a database user with FILE privileges, could possibly use this flaw to run arbitrary commands with root privileges on the system running the database server.
Statement
All MySQL and MariaDB packages in Red Hat Enterprise Linux and Red Hat Software Collections install the my.cnf configuration file in /etc as root-owned and not writeable to mysqld's mysql user. This default configuration stops the published exploit for this issue.
All MySQL and MariaDB packages for Red Hat Enterprise Linux 7 (either those directly included in Red Hat Enterprise Linux 7 or from Red Hat Software Collections for Red Hat Enterprise Linux 7) run mysqld_safe with mysql user privileges and not root privileges, limiting the potential impact to code execution as mysql system user.
The MySQL 5.1 packages in Red Hat Enterprise Linux 6 do not implement support for library preloading, completely preventing the remote attack vector used by the published exploit.
For additional details, refer to:
Mitigation
- Ensure all MySQL / MariaDB configuration files are not writeable to the mysql user. This is the default configuration in Red Hat products.
- Ensure that non-administrative database users are not granted FILE privilege. Applications accessing data in MySQL / MariaDB databases, including web application potentially vulnerable to SQL injections, should use database accounts with the lowest privileges required.
- If FILE permission needs to be granted to some non-administrative database users, use secure_file_priv setting to limit where files can be written to or read from.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 9.8 | 9.8 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | High | High | N/A |
| Integrity Impact | High | High | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v2 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.1 | 10 | N/A |
| Attack Vector | Network | Network | N/A |
| Access Complexity | High | Low | N/A |
| Authentication | Single | None | N/A |
| Confidentiality Impact | Complete | Complete | N/A |
| Integrity Impact | Complete | Complete | N/A |
| Availability Impact | Complete | Complete | N/A |
Vector
Red Hat: AV:N/AC:H/Au:S/C:C/I:C/A:C
NVD: AV:N/AC:L/Au:N/C:C/I:C/A:C
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data; Read Files or Directories
An attacker may be able to read sensitive information from the associated resource, such as credentials or configuration information stored in a file.
Access Control
Technical Impact: Gain Privileges or Assume Identity
An attacker may be able to modify critical properties of the associated resource to gain privileges, such as replacing a world-writable executable with a Trojan horse.
Integrity,Other
Technical Impact: Modify Application Data; Other
An attacker may be able to destroy or corrupt critical data in the associated resource, such as deletion of records from a database.
Frequently Asked Questions
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