30 lines
936 B
Markdown
30 lines
936 B
Markdown
# fail2ban rules for XMPP
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fail2ban rules created to mitigate spambots acting since April 2020.
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Random accounts are created with different IPs (probably zombie machines)
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and then always the same 3 XMPP accounts (on other XMPP servers) are targeted.
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The new chapril account ask for presence subscription to those external JIDs
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and immediately send them random messages without waiting for an answer.
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ejabberd detects the suspicious fast presence subscriptions and logs something
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easy to capture:
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grep Flooder /var/log/ejabberd/ejabberd.log
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So we use these log warnings to trigger IP ban.
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## Quickstart guide
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```
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cd /etc/fail2ban/filter.d
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ln -s /srv/xmpp.chapril.org/tools/fail2ban/filter.d/xmpp-flooders.conf
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cd /etc/fail2ban/jail.d
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ln -s /srv/xmpp.chapril.org/tools/fail2ban/jail.d/chapril-xmpp.conf
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systemctl restart fail2ban
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```
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Check that the jail is active:
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fail2ban-client status
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fail2ban-client status xmpp-c2s
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