The LOAD DATA
statement can load a
file that is located on the server host, or it can load a file
that is located on the client host when the
LOCAL
keyword is specified.
There are two potential security issues with supporting the
LOCAL
version of LOAD
DATA
statements:
The transfer of the file from the client host to the server host is initiated by the MySQL server. In theory, a patched server could be built that would tell the client program to transfer a file of the server's choosing rather than the file named by the client in the
LOAD DATA
statement. Such a server could access any file on the client host to which the client user has read access.In a Web environment where the clients are connecting from a Web server, a user could use
LOAD DATA LOCAL
to read any files that the Web server process has read access to (assuming that a user could run any command against the SQL server). In this environment, the client with respect to the MySQL server actually is the Web server, not the remote program being run by the user who connects to the Web server.
To deal with these problems, we changed how
LOAD DATA
LOCAL
is handled as of MySQL 3.23.49 and MySQL 4.0.2
(4.0.13 on Windows):
By default, all MySQL clients and libraries in binary distributions are compiled with the
-DENABLED_LOCAL_INFILE=1
option, to be compatible with MySQL 3.23.48 and before.If you build MySQL from source but do not invoke CMake with the
-DENABLED_LOCAL_INFILE=1
option,LOAD DATA LOCAL
cannot be used by any client unless it is written explicitly to invokemysql_options(... MYSQL_OPT_LOCAL_INFILE, 0)
. See Section 22.9.3.49, “mysql_options()
”.You can disable all
LOAD DATA LOCAL
statements from the server side by starting mysqld with the--local-infile=0
option.For the mysql command-line client, enable
LOAD DATA LOCAL
by specifying the--local-infile[=1]
option, or disable it with the--local-infile=0
option. For mysqlimport, local data file loading is off by default; enable it with the--local
or-L
option. In any case, successful use of a local load operation requires that the server permits it.If you use
LOAD DATA LOCAL
in Perl scripts or other programs that read the[client]
group from option files, you can add thelocal-infile=1
option to that group. However, to keep this from causing problems for programs that do not understandlocal-infile
, specify it using theloose-
prefix:[client] loose-local-infile=1
If
LOAD DATA LOCAL
is disabled, either in the server or the client, a client that attempts to issue such a statement receives the following error message:ERROR 1148: The used command is not allowed with this MySQL version