This comes from the AbuseIPDB with a confidence level of 95%. I use
the following command to download and sort the IPs:
$ curl -G https://api.abuseipdb.com/api/v2/blacklist -d \
confidenceMinimum=95 -H "Key: $ABUSEIPDB_API_KEY" \
-H "Accept: text/plain" | sort | sed -e '/:/w /tmp/ipv6.txt' \
-e '/:/d' > /tmp/ipv4.txt
I manually add the XML formatting to each file and run them through
tidy:
$ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv4.xml
$ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv6.xml
The WeakDH team showed (in 2015) that Diffie-Hellman key exchange
with prime number groups of 1024 bits or less were weaker than we
previously thought, and well within the reach of nation states. They
recommended (in 2015) using 2048-bit or higher prime groups.
The SSH audit project recommends that we should use 3072-bit now.
See: https://weakdh.org/
See: https://github.com/jtesta/ssh-audit/
We should always restart fail2ban after updating the firewall. Also
note that the order of execution of handlers depends on how they are
defined in the handler config, not on the order they are listed in
the task's notify statement.
See: https://docs.ansible.com/ansible/latest/user_guide/playbooks_handlers.html
This comes from the AbuseIPDB with a confidence level of 95%. I use
the following command to download and sort the IPs:
$ curl -G https://api.abuseipdb.com/api/v2/blacklist -d \
confidenceMinimum=95 -H "Key: $ABUSEIPDB_API_KEY" \
-H "Accept: text/plain" | sort | sed -e '/:/w /tmp/ipv6.txt' \
-e '/:/d' > /tmp/ipv4.txt
I manually add the XML formatting to each file and run them through
tidy:
$ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv4.xml
$ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv6.xml
Note: there were no IPv6 addresses in the top 10,000 this time so I
used a dummy address for the nftables set so the syntax was valid.
After the inital acme.sh script is downloaded and bootstrapped we
can remove it. If a host already has been bootstrapped then there
is no need to download it and do it over again.
It is a standalone package on (at least) Ubuntu 20.04 and Debian 11
and some cloud images do not have it installed by default (for exa-
mple Scaleway).
We have to force these because they are not updated on the host like
the other lists (API limit of five requests per day!). We update the
list periodically here in git.
This comes from the AbuseIPDB with a confidence level of 95%. I use
the following command to download and sort the IPs:
$ curl -G https://api.abuseipdb.com/api/v2/blacklist -d \
confidenceMinimum=95 -H "Key: $ABUSEIPDB_API_KEY" \
-H "Accept: text/plain" | sort | sed -e '/:/w /tmp/ipv6.txt' \
-e '/:/d' > /tmp/ipv4.txt
I manually add the XML formatting to each file and run them through
tidy:
$ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv4.xml
$ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv6.xml
First, we cannot do a global check for has_wordpress or needs_php,
as those are defined per nginx vhost. Second, I realized that this
was only working in the past because vhosts that had WordPress or
needed PHP were listed first in the nginx_vhosts dict.
This changes the logic to first check if any vhosts have WordPress
or need PHP, then sets a fact that we can use to decide whether to
run php-fpm tasks or not.
According to jail.conf we actually need to separate multiple values
with spaces instead of commas. On some versions of fail2ban this is
a fatal error:
> CRITICAL Unhandled exception in Fail2Ban:
> Traceback (most recent call last):
> File "/usr/lib/python3/dist-packages/fail2ban/server/jailthread.py", line 66, in run_with_except_hook
> run(*args, **kwargs)
> File "/usr/lib/python3/dist-packages/fail2ban/server/filtersystemd.py", line 246, in run
> *self.formatJournalEntry(logentry))
> File "/usr/lib/python3/dist-packages/fail2ban/server/filter.py", line 432, in processLineAndAdd
> if self.inIgnoreIPList(ip, log_ignore=True):
> File "/usr/lib/python3/dist-packages/fail2ban/server/filter.py", line 371, in inIgnoreIPList
> "(?<=b)1+", bin(DNSUtils.addr2bin(s[1]))).group())
> File "/usr/lib/python3/dist-packages/fail2ban/server/filter.py", line 928, in addr2bin
> return struct.unpack("!L", socket.inet_aton(ipstring))[0]
> OSError: illegal IP address string passed to inet_aton
This affects (at least) fail2ban 0.9.3 on Ubuntu 16.04, but I never
noticed.
Some hosts can use fail2ban's nginx-botsearch filter to ban anyone
making requests to non-existent files like wp-login.php. There is
no reason to request such files naively and anyone found doing so
can be banned immediately.
In theory I should report them to AbuseIPDB.com, but that will take
a little more wiring up.
For now I am still manually updating this, as we can only hit their
API five times per day, so it is not possible to have each host get
the list themselves every day with our one API key.
This adds Abuse.sh's list of IPs using blacklisted SSL certificates
to nftables. These IPs are high confidence indicators of compromise
and we should not route them. The list is updated daily by a systemd
timer.
See: https://sslbl.abuse.ch/blacklist/
We should only try to start the nftables service after we finish
copying all the config files just in case there is some unclean
state in one of them. On a first run this shouldn't matter, but
after nftables and some abuse list update scripts have run this
can happen (mostly in testing!).
cron-apt updates the system against the security-only databases at
night so many packages are "missing" unless you run apt update. We
need to update the cache on all apt tasks actually because I might
be running them by their tag and they currently only get updated at
the beginning of the playbook.
This opens TCP port 22 on all hosts, TCP ports 80 and 443 on hosts
in the web group, and allows configuration of "extra" rules in the
host or group vars.
I will try using nftables directly instead of via firewalld as of
Debian 11 as it is the replacement for the iptables/ipset stack in
recent years and is easier to work with.
This also includes a systemd service, timer, and script to update
the spamhaus DROP lists as nftables sets.
Still need to add fail2ban support.
Recommended by ssh-audit, but also generally the concensus for a few
years that Encrypt-and-MAC is hard to get right. OpenSSH has several
Encrypt-then-MAC schemes available so we can use those.
See: https://www.daemonology.net/blog/2009-06-24-encrypt-then-mac.html
This was to enable the persistent systemd journal, but it is no lo-
nger needed as of Ubuntu 18.04 and Debian 11. I had removed the ta-
asks long ago, but forgot to remove this file.
This configures the recommended DROP, EDROP, and DROPv6 lists from
Spamhaus as ipsets in firewalld. First we copy an empty placeholder
ipset to seed firewalld, then we use a shell script to download the
real lists and activate them. The same shell script is run daily as
a service (update-spamhaus-lists.service) by a systemd timer.
I am strictly avoiding any direct ipset commands here because I want
to make sure that this works on older hosts where ipsets is used as
well as newer hosts that have moved to nftables such as Ubuntu 20.04.
So far I have tested this on Ubuntu 16.04, 18.04, and 20.04, but ev-
entually I need to abstract the tasks and run them on CentOS 7+ as
well.
See: https://www.spamhaus.org/drop/
This comes from the AbuseIPDB with a confidence level of 95%. I use
the following command to download and sort the IPs:
$ curl -G https://api.abuseipdb.com/api/v2/blacklist -d \
confidenceMinimum=95 -H "Key: $ABUSEIPDB_API_KEY" \
-H "Accept: text/plain" | sort | sed -e '/:/w /tmp/ipv6.txt' \
-e '/:/d' > /tmp/ipv4.txt
I manually add the XML formatting to each file and run them through
tidy:
$ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv4.xml
$ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv6.xml
Instead of manually creating our own self-signed certificate we can
use the one created automatically by the ssl-cert package on Debian.
This is only used by the dummy default HTTPS vhost.
This comes from the AbuseIPDB with a confidence level of 95%. I use
the following command to download and sort the IPs:
$ curl -G https://api.abuseipdb.com/api/v2/blacklist -d \
confidenceMinimum=95 -H "Key: $ABUSEIPDB_API_KEY" \
-H "Accept: text/plain" | sort | sed -e '/:/w /tmp/ipv6.txt' \
-e '/:/d' > /tmp/ipv4.txt
I manually add the XML formatting to each file and run them through
tidy:
$ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv4.xml
$ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv6.xml
This comes from the AbuseIPDB with a confidence level of 95%. I use
the following command to download and sort the IPs:
$ curl -G https://api.abuseipdb.com/api/v2/blacklist -d \
confidenceMinimum=95 -H "Key: $ABUSEIPDB_API_KEY" \
-H "Accept: text/plain" | sort | sed -e '/:/w /tmp/ipv6.txt' \
-e '/:/d' > /tmp/ipv4.txt
I manually add the XML formatting to each file and run them through
tidy:
$ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv4.xml
$ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv6.xml
This comes from the AbuseIPDB with a confidence level of 95%. I use
the following command to download and sort the IPs:
$ curl -G https://api.abuseipdb.com/api/v2/blacklist -d \
confidenceMinimum=95 -H "Key: $ABUSEIPDB_API_KEY" \
-H "Accept: text/plain" | sort | sed -e '/:/w /tmp/ipv6.txt' \
-e '/:/d' > /tmp/ipv4.txt
I manually add the XML formatting to each file and run them through
tidy:
$ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv4.xml
$ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv6.xml
This parameterizes the HTTP Strict Transport Security header so we
can use it consistently across all templates. Also, it updates the
max-age to be ~1 year in seconds, which is recommended by Google.
See: https://hstspreload.org/
The certbot-auto client that I've been using for a long time is now
only supported if you install it using snap. I don't use snap on my
systems so I decided to switch to the acme.sh client, which is imp-
lemented in POSIX shell with no dependencies. One bonus of this is
that I can start using ECC certificates.
This also configures the .well-known directory so we can use webroot
when installing and renewing certificates. I have yet to understand
how the renewal works with regards to webroot, though. I may have to
update the systemd timers to point to /var/lib/letsencrypt/.well-known.
This comes from the AbuseIPDB with a confidence level of 95%. I use
the following command to download and sort the IPs:
$ curl -G https://api.abuseipdb.com/api/v2/blacklist -d \
confidenceMinimum=95 -H "Key: $ABUSEIPDB_API_KEY" \
-H "Accept: text/plain" | sort | sed -e '/:/w /tmp/ipv6.txt' \
-e '/:/d' > /tmp/ipv4.txt
I manually add the XML formatting to each file and run them through
tidy:
$ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv4.xml
$ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv6.xml
Add skip-name-resolve=1 to disable lookups of hostnames to IPs. We
need to make sure all accounts are using IPs like 127.0.0.1 instead
of "localhost" now.
It seems that the usefulness of the query cache is diminishing in
recent years. If your cache is large then the time taken to scan
the cache can be longer than the SQL query itself.
See: https://haydenjames.io/mysql-query-cache-size-performance/
I downloaded the key and checked the fingerprint with gpg:
$ gpg --dry-run --import mariadb_release_signing_key.asc
gpg: key F1656F24C74CD1D8: 6 signatures not checked due to missing keys
gpg: Total number processed: 1
This comes from the AbuseIPDB with a confidence level of 95%. I use
the following command to download and sort the IPs:
$ curl -G https://api.abuseipdb.com/api/v2/blacklist -d \
confidenceMinimum=95 -H "Key: $ABUSEIPDB_API_KEY" \
-H "Accept: text/plain" | sort | sed -e '/:/w /tmp/ipv6.txt' \
-e '/:/d' > /tmp/ipv4.txt
I manually add the XML formatting to each file and run them through
tidy:
$ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv4.xml
$ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv6.xml
This comes from the AbuseIPDB with a confidence level of 95%. I use
the following command to download and sort the IPs:
$ curl -G https://api.abuseipdb.com/api/v2/blacklist -d \
confidenceMinimum=95 -H "Key: $ABUSEIPDB_API_KEY" \
-H "Accept: text/plain" | sort | sed -e '/:/w /tmp/ipv6.txt' \
-e '/:/d' > /tmp/ipv4.txt
I manually add the XML formatting to each file and run them through
tidy:
$ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv4.xml
$ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv6.xml
