Difference between revisions of "Asterisk"
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Jump to navigationJump to search| Line 12: | Line 12: | ||
The second line is what you get if you instruct asterisk to log to syslog by adding <tt>syslog.local0 => notice,warning,error</tt> to <tt>/etc/asterisk/logger.conf</tt> (and obviously configuring your syslogd to log local0 to some file). | The second line is what you get if you instruct asterisk to log to syslog by adding <tt>syslog.local0 => notice,warning,error</tt> to <tt>/etc/asterisk/logger.conf</tt> (and obviously configuring your syslogd to log local0 to some file). | ||
| + | |||
| + | Fail2ban 0.8.3+ recognizes the Asterisk 1.8.x log format and there's no need to enable syslog.local0 as it'll just fill up your messages/syslog file. Use fail2ban-regex to test your conf files and you'll see they're working. | ||
<div style="padding: 1em;border: 1px dashed #2f6fab;color: black;background-color: #f9f9f9;line-height: 1.1em;"> | <div style="padding: 1em;border: 1px dashed #2f6fab;color: black;background-color: #f9f9f9;line-height: 1.1em;"> | ||
| Line 41: | Line 43: | ||
| − | = | + | = Setting Asterisk Conf & Jail Rules = |
| − | + | jail.conf: | |
| − | + | [DEFAULT] | |
| + | bantime = 3600 | ||
| + | findtime = 21600 | ||
| + | maxretry = 3 | ||
| + | backend = auto | ||
| − | |||
[asterisk-iptables] | [asterisk-iptables] | ||
| − | + | # if more than 4 attempts are made within 6 hours, ban for 24 hours | |
enabled = true | enabled = true | ||
filter = asterisk | filter = asterisk | ||
action = iptables-allports[name=ASTERISK, protocol=all] | action = iptables-allports[name=ASTERISK, protocol=all] | ||
sendmail[name=ASTERISK, dest=you@yourmail.co.uk, sender=fail2ban@local.local] | sendmail[name=ASTERISK, dest=you@yourmail.co.uk, sender=fail2ban@local.local] | ||
| − | logpath = /var/log/messages | + | logpath = /var/log/asterisk/messages |
| − | maxretry = | + | maxretry = 4 |
| − | bantime = | + | findtime = 21600 |
| + | bantime = 86400 | ||
| − | + | filter.d/asterisk.conf file for Asterisk 1.4/1.6: | |
# Fail2Ban configuration file | # Fail2Ban configuration file | ||
# | # | ||
# | # | ||
| − | # $Revision: | + | # $Revision: 251 $ |
# | # | ||
| Line 71: | Line 77: | ||
# Read common prefixes. If any customizations available -- read them from | # Read common prefixes. If any customizations available -- read them from | ||
# common.local | # common.local | ||
| − | + | before = common.conf | |
| Line 101: | Line 107: | ||
# | # | ||
ignoreregex = | ignoreregex = | ||
| − | |||
| − | |||
| − | + | filter.d/asterisk.conf file for Asterisk 1.8: | |
| − | + | # Fail2Ban configuration file | |
| − | + | # | |
| − | [ | + | # |
| − | + | # $Revision: 251 $ | |
| − | + | # | |
| + | |||
| + | [INCLUDES] | ||
| + | |||
| + | # Read common prefixes. If any customizations available -- read them from | ||
| + | # common.local | ||
| + | before = common.conf | ||
| + | |||
| + | |||
| + | [Definition] | ||
| + | |||
| + | #_daemon = asterisk | ||
| + | |||
| + | # Option: failregex | ||
| + | # Notes.: regex to match the password failures messages in the logfile. The | ||
| + | # host must be matched by a group named "host". The tag "<HOST>" can | ||
| + | # be used for standard IP/hostname matching and is only an alias for | ||
| + | # (?:::f{4,6}:)?(?P<host>\S+) | ||
| + | # Values: TEXT | ||
| + | # | ||
| + | # Asterisk 1.8 uses Host:Port format which is reflected here | ||
| + | failregex = NOTICE.* .*: Registration from '.*' failed for '<HOST>:.*' - Wrong password | ||
| + | NOTICE.* .*: Registration from '.*' failed for '<HOST>:.*' - No matching peer found | ||
| + | NOTICE.* .*: Registration from '.*' failed for '<HOST>:.*' - No matching peer found | ||
| + | NOTICE.* .*: Registration from '.*' failed for '<HOST>:.*' - Username/auth name mismatch | ||
| + | NOTICE.* .*: Registration from '.*' failed for '<HOST>:.*' - Device does not match ACL | ||
| + | NOTICE.* .*: Registration from '.*' failed for '<HOST>:.*' - Peer is not supposed to register | ||
| + | NOTICE.* .*: Registration from '.*' failed for '<HOST>:.*' - ACL error (permit/deny) | ||
| + | NOTICE.* .*: Registration from '.*' failed for '<HOST>:.*' - Device does not match ACL | ||
| + | NOTICE.* .*: Registration from '\".*\".*' failed for '<HOST>:.*' - No matching peer found | ||
| + | NOTICE.* .*: Registration from '\".*\".*' failed for '<HOST>:.*' - Wrong password | ||
| + | NOTICE.* <HOST> failed to authenticate as '.*'$ | ||
| + | NOTICE.* .*: No registration for peer '.*' \(from <HOST>\) | ||
| + | NOTICE.* .*: Host <HOST> failed MD5 authentication for '.*' (.*) | ||
| + | NOTICE.* .*: Failed to authenticate user .*@<HOST>.* | ||
| + | NOTICE.* .*: <HOST> failed to authenticate as '.*' | ||
| + | NOTICE.* .*: <HOST> tried to authenticate with nonexistent user '.*' | ||
| + | VERBOSE.*SIP/<HOST>-.*Received incoming SIP connection from unknown peer | ||
| + | |||
| + | # Option: ignoreregex | ||
| + | # Notes.: regex to ignore. If this regex matches, the line is ignored. | ||
| + | # Values: TEXT | ||
| + | # | ||
| + | ignoreregex = | ||
[[Category:VOIP]] | [[Category:VOIP]] | ||
Revision as of 14:10, 3 October 2012
Asterisk is an open source VOIP PBX. If you have your asterisk exposed to the Internet, you may see people bruteforcing for usernames and passwords; apart from the obvious security risks, this often occurs at a high rate, causing high CPU and bandwidth usage.
WARNING: There are certain types of asterisk attacks fail2ban is ineffective against. For more details see the discussion page.
Asterisk 1.4 (Debian: 1:1.4.21.2~dfsg-3+lenny1)
The first line is from /var/log/asterisk/messages, which is written by asterisk. It is not usable for fail2ban (0.8.3) because of the timestamp that is enclosed in brackets.
The second line is what you get if you instruct asterisk to log to syslog by adding syslog.local0 => notice,warning,error to /etc/asterisk/logger.conf (and obviously configuring your syslogd to log local0 to some file).
Fail2ban 0.8.3+ recognizes the Asterisk 1.8.x log format and there's no need to enable syslog.local0 as it'll just fill up your messages/syslog file. Use fail2ban-regex to test your conf files and you'll see they're working.
- [Aug 8 14:31:33] NOTICE[1687] chan_sip.c: Registration from '"150"<sip:150@hostname>' failed for '192.0.2.1' - No matching peer found
- Aug 8 14:31:33 hostname asterisk[1617]: NOTICE[1687]: chan_sip.c:15642 in handle_request_register: Registration from '"154"<sip:154@hostname>' failed for '192.0.2.1' - No matching peer found
05/14/2011 - Don't forget to add this to /etc/asterisk/logger.conf. [general] dateformat=%F %T Thats important, otherwise fail2ban will will not be able to properly parse the log file. FSD
Failregex
The regular expressions below are proposed failregex for this software. Multiple regular expressions for failregex will only work with a version of Fail2ban greater than or equal to 0.7.6.
The tag <HOST> in the regular expressions below is just an alias for (?:::f{4,6}:)?(?P<host>\S+). The replacement is done automatically by Fail2ban when adding the regular expression. At the moment, exactly one named group host or <HOST> tag must be present in each regular expression.
Please, before editing this section, propose your changes in the discussion page first.
failregex = asterisk.*chan_sip.c.*Registration from .* failed for '<HOST>' - No matching peer found
Setting Asterisk Conf & Jail Rules
jail.conf:
[DEFAULT] bantime = 3600 findtime = 21600 maxretry = 3 backend = auto
[asterisk-iptables]
# if more than 4 attempts are made within 6 hours, ban for 24 hours
enabled = true
filter = asterisk
action = iptables-allports[name=ASTERISK, protocol=all]
sendmail[name=ASTERISK, dest=you@yourmail.co.uk, sender=fail2ban@local.local]
logpath = /var/log/asterisk/messages
maxretry = 4
findtime = 21600
bantime = 86400
filter.d/asterisk.conf file for Asterisk 1.4/1.6:
# Fail2Ban configuration file
#
#
# $Revision: 251 $
#
[INCLUDES]
# Read common prefixes. If any customizations available -- read them from
# common.local
before = common.conf
[Definition]
#_daemon = asterisk
# Option: failregex
# Notes.: regex to match the password failures messages in the logfile. The
# host must be matched by a group named "host". The tag "<HOST>" can
# be used for standard IP/hostname matching and is only an alias for
# (?:::f{4,6}:)?(?P<host>\S+)
# Values: TEXT
#
failregex = NOTICE.* .*: Registration from '.*' failed for '<HOST>' - Wrong password
NOTICE.* .*: Registration from '.*' failed for '<HOST>' - No matching peer found
NOTICE.* .*: Registration from '.*' failed for '<HOST>' - Username/auth name mismatch
NOTICE.* <HOST> failed to authenticate as '.*'$
NOTICE.* .*: No registration for peer '.*' (from )
NOTICE.* .*: Host failed MD5 authentication for '.*' (.*)
NOTICE.* .*: Registration from '.*' failed for '<HOST>' - Device does not match ACL
NOTICE.* .*: Registration from '.*" .* failed for '<HOST>' - Peer is not supposed to register
VERBOSE.*SIP/<HOST>-.*Received incoming SIP connection from unknown peer
# Option: ignoreregex
# Notes.: regex to ignore. If this regex matches, the line is ignored.
# Values: TEXT
#
ignoreregex =
filter.d/asterisk.conf file for Asterisk 1.8:
# Fail2Ban configuration file
#
#
# $Revision: 251 $
#
[INCLUDES]
# Read common prefixes. If any customizations available -- read them from
# common.local
before = common.conf
[Definition]
#_daemon = asterisk
# Option: failregex
# Notes.: regex to match the password failures messages in the logfile. The
# host must be matched by a group named "host". The tag "<HOST>" can
# be used for standard IP/hostname matching and is only an alias for
# (?:::f{4,6}:)?(?P<host>\S+)
# Values: TEXT
#
# Asterisk 1.8 uses Host:Port format which is reflected here
failregex = NOTICE.* .*: Registration from '.*' failed for '<HOST>:.*' - Wrong password
NOTICE.* .*: Registration from '.*' failed for '<HOST>:.*' - No matching peer found
NOTICE.* .*: Registration from '.*' failed for '<HOST>:.*' - No matching peer found
NOTICE.* .*: Registration from '.*' failed for '<HOST>:.*' - Username/auth name mismatch
NOTICE.* .*: Registration from '.*' failed for '<HOST>:.*' - Device does not match ACL
NOTICE.* .*: Registration from '.*' failed for '<HOST>:.*' - Peer is not supposed to register
NOTICE.* .*: Registration from '.*' failed for '<HOST>:.*' - ACL error (permit/deny)
NOTICE.* .*: Registration from '.*' failed for '<HOST>:.*' - Device does not match ACL
NOTICE.* .*: Registration from '\".*\".*' failed for '<HOST>:.*' - No matching peer found
NOTICE.* .*: Registration from '\".*\".*' failed for '<HOST>:.*' - Wrong password
NOTICE.* <HOST> failed to authenticate as '.*'$
NOTICE.* .*: No registration for peer '.*' \(from <HOST>\)
NOTICE.* .*: Host <HOST> failed MD5 authentication for '.*' (.*)
NOTICE.* .*: Failed to authenticate user .*@<HOST>.*
NOTICE.* .*: <HOST> failed to authenticate as '.*'
NOTICE.* .*: <HOST> tried to authenticate with nonexistent user '.*'
VERBOSE.*SIP/<HOST>-.*Received incoming SIP connection from unknown peer
# Option: ignoreregex
# Notes.: regex to ignore. If this regex matches, the line is ignored.
# Values: TEXT
#
ignoreregex =
