Although vsftpd may not offer the level of
customization other widely available FTP servers have, it offers
enough options to fill most administrator's needs. The fact that it is
not overly feature-laden limits configuration and programmatic errors.
All configuration of vsftpd is handled by its
configuration file, /etc/vsftpd/vsftpd.conf. Each
directive is on its own line within the file and follows the following
format:
<directive>=<value>
For each directive, replace
<directive> with a valid directive
and <value> with a valid value.
Important
There must not be any spaces between the
<directive>, equal symbol, and the
<value> in a directive.
Comment lines must be preceded by a hash mark (#)
and are ignored by the daemon.
For a complete list of all directives available, refer to the man page
for vsftpd.conf.
Important
For an overview of
ways to secure vsftpd, refer to the chapter titled
Server Security in the
Red Hat Enterprise Linux Security Guide.
The following is a list of some of the more important directives
within /etc/vsftpd/vsftpd.conf. All directives
not explicitly found within vsftpd's configuration
file are set to their default value.
The following is a list of directives which control the overall
behavior of the vsftpd daemon.
listen — When enabled,
vsftpd runs in stand-alone mode. Red Hat Enterprise Linux sets
this value to YES. This directive cannot be
used in conjunction with the listen_ipv6
directive.
The default value is NO.
listen_ipv6 — When enabled,
vsftpd runs in stand-alone mode, but listens
only to IPv6 sockets. This directive cannot be used in conjunction
with the listen directive.
The default value is NO.
session_support — When enabled,
vsftpd attempts to maintain login sessions
for each user through Pluggable Authentication Modules
(PAM). Refer to Chapter 16 Pluggable Authentication Modules (PAM) for more information. If
session logging is not necessary, disabling this option allows
vsftpd to run with less processes and lower
privileges.
banned_email_file — If the
deny_email_enable directive is set to
YES, this directive specifies the file
containing a list of anonymous email passwords which are not
permitted access to the server.
The default value is
/etc/vsftpd.banned_emails.
banner_file — Specifies the file
containing text displayed when a connection is established to
the server. This option overrides any text specified in the
ftpd_banner directive.
There is no default value for this directive.
cmds_allowed — Specifies a
comma-delimited list of FTP commands allowed by the server. All
other commands are rejected.
There is no default value for this directive.
deny_email_enable — When enabled,
any anonymous user using email passwords specified in the
/etc/vsftpd.banned_emails are denied access
to the server. The name of the file referenced by this directive
can be specified using the banned_email_file
directive.
The default value is NO.
ftpd_banner — When enabled, the
string specified within this directive is displayed when a
connection is established to the server. This option can be
overridden by the banner_file directive.
By default vsftpd displays its standard banner.
local_enable — When enabled, local
users are allowed to log into the system.
pam_service_name — Specifies the
PAM service name for vsftpd.
The default value is ftp. Note, in
Red Hat Enterprise Linux, the value is set to vsftpd.
tcp_wrappers — When enabled, TCP
wrappers are used to grant access to the server. If the
FTP server is configured on multiple IP addresses, the
VSFTPD_LOAD_CONF option can be used to load
different configuration files based on the IP address being
requested by the client. For more information about TCP
Wrappers, refer to Chapter 17 TCP Wrappers and xinetd.
The default value is NO. Note, in
Red Hat Enterprise Linux, the value is set to YES.
userlist_deny — When used in
conjunction with the userlist_enable
directive and set to NO, all local users are
denied access unless the username is listed in the file
specified by the userlist_file
directive. Because access is denied before the client is asked
for a password, setting this directive to NO
prevents local users from submitting unencrypted passwords over
the network.
The default value is YES.
userlist_enable — When enabled, the
users listed in the file specified by the
userlist_file directive are denied
access. Because access is denied before the client is asked for
a password, users are prevented from submitting unencrypted
passwords over the network.
The default value is NO, however under
Red Hat Enterprise Linux the value is set to YES.
userlist_file — Specifies the file
referenced by vsftpd when the
userlist_enable directive is enabled.
The default value is
/etc/vsftpd.user_list and is created during
installation.
cmds_allowed — Specifies a comma
separated list of FTP commands that the server allows. Any
other commands are rejected.
The following lists directives which control anonymous user
access to the server. To use these options, the
anonymous_enable directive must be set to
YES.
anon_mkdir_write_enable — When
enabled in conjunction with the write_enable
directive, anonymous users are allowed to create new directories
within a parent directory which has write permissions.
The default value is NO.
anon_root — Specifies the directory
vsftpd changes to after an anonymous user logs
in.
There is no default value for this directive.
anon_upload_enable — When
enabled in conjunction with the write_enable
directive, anonymous users are allowed to upload files
within a parent directory which has write permissions.
The default value is NO.
anon_world_readable_only — When
enabled, anonymous users are only allowed to download
world-readable files.
The default value is YES.
ftp_username — Specifies the local
user account (listed in /etc/passwd) used
for the anonymous FTP user. The home directory specified in
/etc/passwd for the user is the root
directory of the anonymous FTP user.
The default value is ftp.
no_anon_password — When enabled,
the anonymous user is not asked for a password.
The default value is NO.
secure_email_list_enable — When
enabled, only a specified list of email passwords for anonymous
logins are accepted. This is a convenient way to offer limited
security to public content without the need for virtual users.
Anonymous logins are prevented unless the password provided
is listed in /etc/vsftpd.email_passwords. The
file format is one password per line, with no trailing
white spaces.
The following lists directives which characterize the way
local users access the server. To use these options, the
local_enable directive must be set to
YES.
chmod_enable — When enabled, the
FTP command SITE CHMOD is allowed for local
users. This command allows the users to change the permissions
on files.
The default value is YES.
chroot_list_enable — When enabled,
the local users listed in the file specified in the
chroot_list_file directive are placed in a
chroot jail upon log in.
If enabled in conjunction with the
chroot_local_user directive, the local users
listed in the file specified in the
chroot_list_file directive are
not placed in a chroot
jail upon log in.
The default value is NO.
chroot_list_file — Specifies the
file containing a list of local users referenced when the
chroot_list_enable directive is set to
YES.
The default value is
/etc/vsftpd.chroot_list.
chroot_local_user — When enabled,
local users are change-rooted to their home directories after
logging in.
The default value is NO.
Warning
Enabling chroot_local_user opens up a
number of security issues, especially for users with upload
privileges. For this reason, it is not
recommended.
guest_enable — When enabled, all
non-anonymous users are logged in as the user
guest, which is the local user specified in
the guest_username directive.
The default value is NO.
guest_username — Specifies the
username the guest user is mapped to.
The default value is ftp.
local_root — Specifies the
directory vsftpd changes to after a local
user logs in.
There is no default value for this directive.
local_umask — Specifies the umask
value for file creation. Note that the default value is in octal
form (a numerical system with a base of eight), which includes a
"0" prefix. Otherwise the value is treated as a base-10 integer.
The default value is 022.
passwd_chroot_enable — When enabled
in conjunction with the chroot_local_user
directive, vsftpd change-roots local users
based on the occurrence of the /./ in the home
directory field within /etc/passwd.
The default value is NO.
user_config_dir — Specifies the
path to a directory containing configuration files bearing the
name of local system users that contain specific setting for
that user. Any directive in the user's configuration file
overrides those found in /etc/vsftpd/vsftpd.conf.
The following lists directives which affect directories.
dirlist_enable — When enabled,
users are allowed to view directory lists.
The default value is YES.
dirmessage_enable — When enabled, a
message is displayed whenever a user enters a directory with a
message file. This message is found within the directory being
entered. The name of this file is specified in the
message_file directive and is
.message by default.
The default value is NO. Note, in
Red Hat Enterprise Linux, the value is set to YES.
force_dot_files — When enabled,
files beginning with a dot (.)
are listed in directory listings, with the exception of the
. and .. files.
The default value is NO.
hide_ids — When enabled, all
directory listings show ftp as
the user and group for each file.
The default value is NO.
message_file — Specifies the name
of the message file when using the
dirmessage_enable directive.
The default value is .message.
text_userdb_names — When enabled,
test usernames and group names are used in place of UID and GID
entries. Enabling this option may slow performance of the server.
The default value is NO.
use_localtime — When enabled,
directory listings reveal the local time for the computer instead
of GMT.
The following lists directives which affect
vsftpd's logging behavior.
dual_log_enable — When enabled in
conjunction with xferlog_enable,
vsftpd writes two files simultaneously: a
wu-ftpd-compatible log to the file specified
in the xferlog_file directive
(/var/log/xferlog by default) and a
standard vsftpd log file specified in the
vsftpd_log_file directive
(/var/log/vsftpd.log by default).
The default value is NO.
log_ftp_protocol — When enabled in
conjunction with xferlog_enable and with
xferlog_std_format set to
NO, all FTP commands and responses are
logged. This directive is useful for debugging.
The default value is NO.
syslog_enable — When enabled in
conjunction with xferlog_enable, all
logging normally written to the standard
vsftpd log file specified in the
vsftpd_log_file directive
(/var/log/vsftpd.log by default) is sent to
the system logger instead under the FTPD facility.
The default value is NO.
vsftpd_log_file — Specifies the
vsftpd log file. For this file to be used,
xferlog_enable must be enabled and
xferlog_std_format must either be set to
NO or, if xferlog_std_format
is set to YES,
dual_log_enable must be enabled. It is
important to note that if syslog_enable is set
to YES, the system log is used instead of the
file specified in this directive.
The default value is
/var/log/vsftpd.log.
xferlog_enable — When enabled,
vsftpd logs connections
(vsftpd format only) and file transfer
information to the log file specified in the
vsftpd_log_file directive
(/var/log/vsftpd.log by default). If
xferlog_std_format is set to
YES, file transfer
information is logged but connections are not, and the log
file specified in xferlog_file
(/var/log/xferlog by default) is used
instead. It is important to note that both log files and log
formats are used if dual_log_enable is set to
YES.
The default value is NO. Note, in
Red Hat Enterprise Linux, the value is set to YES.
xferlog_file — Specifies the
wu-ftpd-compatible log file. For this file to
be used, xferlog_enable must be enabled and
xferlog_std_format must be set to
YES. It is also used if
dual_log_enable is set to
YES.
The default value is
/var/log/xferlog.
xferlog_std_format — When enabled
in conjunction with xferlog_enable, only a
wu-ftpd-compatible file transfer log is
written to the file specified in the
xferlog_file directive
(/var/log/xferlog by default). It is
important to note that this file only logs file transfers and
does not log connections to the server.
The default value is NO. Note, in
Red Hat Enterprise Linux, the value is set to YES.
Important
To maintain compatibility with log files written by the older
wu-ftpd FTP server, the
xferlog_std_format directive is set to
YES under Red Hat Enterprise Linux. However, this setting means
that connections to the server are not logged.
To both log connections in vsftpd format and
maintain a wu-ftpd-compatible file transfer log,
set dual_log_enable to YES.
If maintaining a wu-ftpd-compatible file transfer
log is not important, either set xferlog_std_format to
NO, comment the line with a hash mark
(#), or delete the line entirely.
The following lists directives which affect how
vsftpd interacts with the network.
accept_timeout — Specifies the
amount of time for a client using passive mode to establish a
connection.
The default value is 60.
anon_max_rate — Specifies the
maximum data transfer rate for anonymous users in bytes per
second.
The default value is 0, which does not limit
the transfer rate.
connect_from_port_20 When enabled,
vsftpd runs with enough privileges to open
port 20 on the server during active mode data
transfers. Disabling this option allows
vsftpd to run with less privileges, but may
be incompatible with some FTP clients.
The default value is NO. Note, in Red Hat Enterprise Linux,
the value is set to YES.
connect_timeout — Specifies the
maximum amount of time a client using active mode has to respond to a
data connection, in seconds.
The default value is 60.
data_connection_timeout — Specifies
maximum amount of time data transfers are allowed to stall, in
seconds. Once triggered, the connection to the remote client is
closed.
The default value is 300.
ftp_data_port — Specifies the port
used for active data connections when
connect_from_port_20 is set to
YES.
The default value is 20.
idle_session_timeout — Specifies
the maximum amount of time between commands from a remote
client. Once
triggered, the connection to the remote client is closed.
The default value is 300.
listen_address — Specifies the IP
address on which vsftpd listens for network
connections.
There is no default value for this directive.
Tip
If running multiple copies of vsftpd
serving different IP addresses, the configuration file for
each copy of the vsftpd daemon must have a
different value for this directive. Refer to Section 15.4.1 Starting Multiple Copies of vsftpd for more information
about multihomed FTP servers.
listen_address6 — Specifies the
IPv6 address on which vsftpd listens for
network connections when listen_ipv6 is set to
YES.
There is no default value for this directive.
Tip
If running multiple copies of vsftpd serving
different IP addresses, the configuration file for each copy of
the vsftpd daemon must have a different value
for this directive. Refer to Section 15.4.1 Starting Multiple Copies of vsftpd for more information about
multihomed FTP servers.
listen_port — Specifies the port on
which vsftpd listens for network connections.
The default value is 21.
local_max_rate — Specifies the
maximum rate data is transfered for local users logged into the
server in bytes per second.
The default value is 0, which does not limit
the transfer rate.
max_clients — Specifies the maximum
number of simultaneous clients allowed to connect to the server
when it is running in standalone mode. Any additional client
connections would result in an error message.
The default value is 0, which does not limit
connections.
max_per_ip — Specifies the maximum
of clients allowed to connected from the same source IP address.
The default value is 0, which does not limit
connections.
pasv_address — Specifies the IP
address for the public facing IP address of the server for servers
behind Network Address Translation (NAT) firewalls. This enables
vsftpd to hand out the correct return address
for passive mode connections.
There is no default value for this directive.
pasv_enable — When enabled, passive
mode connects are allowed.
The default value is YES.
pasv_max_port — Specifies the highest
possible port sent to the FTP clients for passive mode
connections. This setting is used to limit the port range so that
firewall rules are easier to create.
The default value is 0, which does not
limit the highest passive port range. The value must not exceed
65535.
pasv_min_port — Specifies the lowest
possible port sent to the FTP clients for passive mode
connections. This setting is used to limit the port range so that
firewall rules are easier to create.
The default value is 0, which does not
limit the lowest passive port range. The value must not be
lower 1024.
pasv_promiscuous — When enabled, data
connections are not checked to make sure they are originating
from the same IP address. This setting is only useful for certain
types of tunneling.
Caution
Do not enable this option unless absolutely necessary as it
disables an important security feature which verifies that
passive mode connections originate from the same IP address as
the control connection that initiates the data transfer.
The default value is NO.
port_enable — When enabled, active
mode connects are allowed.
