Bug 1802786 (CVE-2020-7221)

Summary:	CVE-2020-7221 mariadb: mysql_install_db allows privilege escalation due to unsafe chown and chmod operations
Product:	[Other] Security Response	Reporter:	Guilherme de Almeida Suckevicz <gsuckevi>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	databases-maint, dbecker, dciabrin, hhorak, jjanco, jjoyce, jorton, jschluet, jstanek, kbasil, lhh, ljavorsk, lpeer, mbayer, mburns, mkocka, mmuzila, mschorm, sclewis, slinaber, SpikeFedora
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	mariadb 10.5.1, mariadb 10.4.12	Doc Type:	If docs needed, set a value
Doc Text:	A privilege escalation vulnerability was found in MariaDB, in the way it handled a `setuid` program during the installation process. A local MySQL user could abuse this flaw to escalate their privileges on the system, by gaining root privileges once the bash script `mysql_install_db.sh` is executed.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-02-24 15:39:14 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1802787, 1802788
Bug Blocks:	1802789

Description Guilherme de Almeida Suckevicz 2020-02-13 20:42:00 UTC

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.

Reference:
https://seclists.org/oss-sec/2020/q1/55

Upstream commit:
https://github.com/MariaDB/server/commit/9d18b6246755472c8324bf3e20e234e08ac45618

Comment 1 Guilherme de Almeida Suckevicz 2020-02-13 20:43:20 UTC

Created mariadb tracking bugs for this issue:

Affects: fedora-all [bug 1802787]
Affects: openstack-rdo [bug 1802788]

Comment 2 Mauro Matteo Cascella 2020-02-24 14:47:39 UTC

Plugin `auth_pam_tool` was introduced in MariaDB upstream version 10.4.0 with the following commits:
https://github.com/MariaDB/server/commit/efba0b1df5abe1ac972181a01bcbd208693639ae
https://github.com/MariaDB/server/commit/25410d448d5cd5796852da106324309d169981c9

The setuid permission was set in MariaDB upstream version 10.4.7 with commit:
https://github.com/MariaDB/server/commit/ec494cb1fadb40ae25b944bb1229fc2d6f88e8c6

Comment 3 Mauro Matteo Cascella 2020-02-24 15:26:47 UTC

Statement:

This flaw did not affect the versions of MariaDB as shipped with Red Hat Enterprise Linux 7, and 8 as they did not include the vulnerable code, which was introduced in a newer version of the package. The same is true for the versions of MariaDB as shipped with Red Hat Software Collections 3.