Bug 1301493 (CVE-2016-0546)

Created mariadb tracking bugs for this issue:

Affects: fedora-all [bug 1301518]

Created community-mysql tracking bugs for this issue:

Affects: fedora-all [bug 1301517]

Created mariadb-galera tracking bugs for this issue:

Affects: fedora-all [bug 1301519]

Looking at the changes applied between upstream versions 5.5.46 and 5.5.47, the only Client-related commit is:

https://github.com/mysql/mysql-server/commit/0dbd5a8797ed4bd18e8b883988fb62177eb0f73f

This change is also described in the 5.5.47 and 5.6.28 release notes:

  Possible buffer overflow from incorrect use of strcpy() and sprintf() was
  corrected. (Bug #21973610)

http://dev.mysql.com/doc/relnotes/mysql/5.5/en/news-5-5-47.html
http://dev.mysql.com/doc/relnotes/mysql/5.6/en/news-5-6-28.html

There are multiple fixes applied as part of that commit:


* mysql_plugin strcpy() buffer overflow, triggered by excessively long command line argument.  This tool is meant for use by system/database administrator and its arguments are trusted input.  There's no trust boundary bypass.

Affected strcpy() calls use static buffer as the destination, so the overflow is detected by FORTIFY_SOURCE, leading to program abort before any overflow actually happens.

The mysql_plugin tool was introduced in MySQL 5.5, hence older versions (such as MySQL 5.1 in Red Hat Enterprise Linux 6) are not affected by this problem.


* mysqlshow multiple strcpy() buffer overflows.  As with the mysql_plugin above, these are mitigated by FORTIFY_SOURCE to application abort without any code execution impact.  Some are triggered by command line arguments, others may be triggered by long database or table names.  It does not seem databases or tables with long names created in a trusted database server can trigger these overflows, as buffers used were large enough to hold names following the MySQL limit on maximum name length.  A malicious or compromised database server may be able to trigger these.


* mysqlshow multiple strmov()/strxmov() buffer overflows.  strmov() is a strcpy()-like function, and strxmov() is strmov() which accepts multiple source strings.  Exploitation of these overflows is made harder by the use of stack smashing protector, which triggers application abort at the end of the function where overflow happens.

- list_table_status() - arguments to str*mov() come from mysqlshow's command line arguments, therefore no trust boundary is bypassed.

- list_fields() - depending on how mysqlshow is run, arguments to str*mov() can either be command line arguments or table names returned by the server.  As with the strcpy() overflows above, a malicious or compromised database server is required to trigger this flaw.


* conf_to_src and regex/main sprintf() buffer overs.  These are some helper tools apparently used by MySQL developers, but not part of the MySQL packages as shipped with Red Hat products.  Therefore, these issues have no impact.

The overflow impact of these issues is very limited, as explained in the comment above.  Upstream rating seems rather incorrect.  There's only any impact if the mysqlshow tool is used to find out information about database or tables on some malicious MySQL server.

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2016:0534 https://rhn.redhat.com/errata/RHSA-2016-0534.html

This issue has been addressed in the following products:

  Red Hat Software Collections for Red Hat Enterprise Linux 7.1 EUS
  Red Hat Software Collections for Red Hat Enterprise Linux 7.2 EUS
  Red Hat Software Collections for Red Hat Enterprise Linux 6.6 EUS
  Red Hat Software Collections for Red Hat Enterprise Linux 6.7 EUS
  Red Hat Software Collections for Red Hat Enterprise Linux 6
  Red Hat Software Collections for Red Hat Enterprise Linux 7

Via RHSA-2016:0705 https://rhn.redhat.com/errata/RHSA-2016-0705.html

This issue has been addressed in the following products:

  Red Hat Software Collections for Red Hat Enterprise Linux 7.1 EUS
  Red Hat Software Collections for Red Hat Enterprise Linux 7.2 EUS
  Red Hat Software Collections for Red Hat Enterprise Linux 7
  Red Hat Software Collections for Red Hat Enterprise Linux 6.6 EUS
  Red Hat Software Collections for Red Hat Enterprise Linux 6
  Red Hat Software Collections for Red Hat Enterprise Linux 6.7 EUS

Via RHSA-2016:1132 https://access.redhat.com/errata/RHSA-2016:1132

This issue has been addressed in the following products:

  Red Hat Software Collections for Red Hat Enterprise Linux 6
  Red Hat Software Collections for Red Hat Enterprise Linux 6.6 EUS
  Red Hat Software Collections for Red Hat Enterprise Linux 6.7 EUS
  Red Hat Software Collections for Red Hat Enterprise Linux 7.2 EUS
  Red Hat Software Collections for Red Hat Enterprise Linux 7.1 EUS
  Red Hat Software Collections for Red Hat Enterprise Linux 7

Via RHSA-2016:1481 https://rhn.redhat.com/errata/RHSA-2016-1481.html

This issue has been addressed in the following products:

  Red Hat Software Collections for Red Hat Enterprise Linux 6
  Red Hat Software Collections for Red Hat Enterprise Linux 6.6 EUS
  Red Hat Software Collections for Red Hat Enterprise Linux 6.7 EUS
  Red Hat Software Collections for Red Hat Enterprise Linux 7.2 EUS
  Red Hat Software Collections for Red Hat Enterprise Linux 7.1 EUS
  Red Hat Software Collections for Red Hat Enterprise Linux 7

Via RHSA-2016:1480 https://rhn.redhat.com/errata/RHSA-2016-1480.html