3.7 KiB
Hardening your instance
Here are some suggestions which improve the security of parts of your Pleroma instance.
Configuration file
These changes should go into prod.secret.exs
or dev.secret.exs
, depending on your MIX_ENV
value.
http
Recommended value:
[ip: {127, 0, 0, 1}]
This sets the Pleroma application server to only listen to the localhost interface. This way, you can only reach your server over the Internet by going through the reverse proxy. By default, Pleroma listens on all interfaces.
secure_cookie_flag
Recommended value:
true
This sets the secure
flag on Pleroma’s session cookie. This makes sure, that the cookie is only accepted over encrypted HTTPs connections. This implicitly renames the cookie from pleroma_key
to __Host-pleroma-key
which enforces some restrictions. (see cookie prefixes)
:http_security
Recommended value:
true
This will send additional HTTP security headers to the clients, including:
X-XSS-Protection: "1; mode=block"
X-Permitted-Cross-Domain-Policies: "none"
X-Frame-Options: "DENY"
X-Content-Type-Options: "nosniff"
X-Download-Options: "noopen"
A content security policy (CSP) will also be set:
content-security-policy:
default-src 'none';
base-uri 'self';
frame-ancestors 'none';
img-src 'self' data: https:;
media-src 'self' https:;
style-src 'self' 'unsafe-inline';
font-src 'self';
script-src 'self';
connect-src 'self' wss://example.tld;
manifest-src 'self';
upgrade-insecure-requests;
sts
Recommended value:
true
An additional “Strict transport security” header will be sent with the configured sts_max_age
parameter. This tells the browser, that the domain should only be accessed over a secure HTTPs connection.
ct_max_age
An additional “Expect-CT” header will be sent with the configured ct_max_age
parameter. This enforces the use of TLS certificates that are published in the certificate transparency log. (see Expect-CT)
referrer_policy
Recommended value:
same-origin
If you click on a link, your browser’s request to the other site will include from where it is coming from. The “Referrer policy” header tells the browser how and if it should send this information. (see Referrer policy)
systemd
A systemd unit example is provided at installation/pleroma.service
.
PrivateTmp
Recommended value:
true
Use private /tmp
and /var/tmp
folders inside a new file system namespace, which are discarded after the process stops.
ProtectHome
Recommended value:
true
The /home
, /root
, and /run/user
folders can not be accessed by this service anymore. If your Pleroma user has its home folder in one of the restricted places, or use one of these folders as its working directory, you have to set this to false
.
ProtectSystem
Recommended value:
full
Mount /usr
, /boot
, and /etc
as read-only for processes invoked by this service.
PrivateDevices
Recommended value:
true
Sets up a new /dev
mount for the process and only adds API pseudo devices like /dev/null
, /dev/zero
or /dev/random
but not physical devices. This may not work on devices like the Raspberry Pi, where you need to set this to false
.
NoNewPrivileges
Recommended value:
true
Ensures that the service process and all its children can never gain new privileges through execve()
.
CapabilityBoundingSet
Recommended value:
~CAP_SYS_ADMIN
Drops the sysadmin capability from the daemon.