Hardening - Application Recommendations

For general hardening guidelines, see the main hardening documentation.

You control the hardening recommendations for GitLab instances through the web interface.

System hooks

  1. On the left sidebar, at the bottom, select Admin area.
  2. Select System hooks.

In a typical hardened environment, internal information is not transmitted or stored outside of the system. For an offline environment system, this is implied. System hooks provide a way for local events in the environment to communicate information outside of the environment based upon triggers.

Use cases for this capability are supported, particularly monitoring the system through a remote system. However, you must apply extreme caution when deploying system hooks. For hardened systems, if they are intended to be an offline environment, a perimeter of trusted systems allowed to communicate with each other must be enforced, so any hooks (system, web, or file) must only communicate with those trusted systems. TLS is strongly encouraged for communications through system hooks.

Push rules

  1. On the left sidebar, at the bottom, select Admin area.
  2. Select Push rules.

Ensure that the following items are selected:

  • Reject unverified users
  • Do not allow users to remove Git tags with git push
  • Check whether the commit author is a GitLab user
  • Prevent pushing secret files

The adjustments help limit pushes to established and authorized users.

Deploy keys

  1. On the left sidebar, at the bottom, select Admin area.
  2. Select Deploy keys.

Public deploy keys at are used to give read or read/write access to all projects on the instance, and are intended for remote automation to access projects. Public deploy keys should not be used in a hardened environment. If you must use deploy keys, use project deploy keys instead. For more information, refer to the documentation on deploy keys and project deploy keys.

General

  1. On the left sidebar, at the bottom, select Admin area.
  2. Select Settings > General.

Hardening adjustments can be made in 4 sections.

Visibility and access control

The default for the following settings is Private:

  • Default project visibility
  • Default snippet visibility
  • Default group visibility

Only users that are granted specific access to a project, snippet, or group can access these resources. This can be adjusted later as needed or at the time of their creation. This helps prevent accidental or malicious disclosure of information.

Depending on your security policy and posture, you might wish to set your Restricted visibility level to Public, as this prevents user profiles from being viewed by non-authenticated users.

In Import sources, select only the sources you really need.

A typical deployment has Enabled Git access protocols set to Both SSH and HTTP(S), however if one of the Git protocols is not in use by your users, set it to either Only SSH or Only HTTP(S) accordingly. This helps shrink the attack surface.

For SSH key types, the following are preferred: ED25519 (and ED25519-SK), RSA, and ECDSA (and ECDSA-SK) in that order. ED25519 is considered as secure as RSA when RSA is set to 2048 bits or higher, however the ED25519 keys are smaller and the algorithm is much faster.

ED25519-SK and ECDSA-SK both end with -SK which stands for “Security Key”. The -SK types are compatible with FIDO/U2F standards and pertain to usage with hardware tokens, for example YubiKeys.

DSA should be set to “Are forbidden”. DSA has known flaws, and many cryptographers are suspicious of and do not support using ECDSA.

If GitLab is in FIPS mode, use the following:

  • If running in FIPS mode:
    • Use RSA, set to Must be at least 2048 bits.
    • Use ECDSA (and ECDSA-SK), set to Must be at least 256 bits.
    • Set all other key types to Are forbidden. RSA and ECDSA are both approved for FIPS use.
  • If not running in FIPS mode, you must use ED25519 and can also use RSA:
    • Set ED25519 (and ED25519-SK) to Must be at least 256 bits.
    • If using RSA, set it to Must be at least 2048 bits.
    • Set all other key types to Are forbidden.
  • If you are setting up an instance for a new group of users, define your user SSH key policy with the maximum bits settings for added security.

In a hardened environment RSS feeds are typically not required, and in Feed token, select the Disabled feed token checkbox.

If all of your users are coming from specific IP addresses, use Global-allowed IP ranges to specifically allow only those addresses.

For more details on Visibility and access control, see visibility and access controls. For information on SSH settings, see SSH keys restrictions.

Account and limit

For hardening purposes, ensure the checkbox next to Gravatar enabled is not selected. All extraneous communications should be curtailed, and in some environments might be restricted. Account avatars can be manually uploaded by users.

The settings in this section are intended to help enforce a custom implementation of your own specific standards on your users. As the various scenarios are too many and too varied, you should review the account and limit settings documentation and apply changes to enforce your own policies.

Sign-up restrictions

Ensure open sign-up is disabled on your hardened instance. Ensure the Sign-up enabled checkbox is not selected.

In Email confirmation settings, ensure that Hard is selected. User verification of their email address is now enforced before access is granted.

The Minimum password length (number of characters) default setting is 12 which should be fine as long as additional authentication techniques are used. The password should be complex, so ensure that all four of these checkboxes are selected:

  • Require numbers
  • Require uppercase letters
  • Require lowercase letters
  • Require symbols

If all of your users belong to the same organization that uses a specific domain for email addresses, then list that domain in Allowed domains for sign-ups. This prevents those with email addresses in other domains from signing up.

For more detailed information, see sign-up restrictions.

Sign-in restrictions

Two-factor authentication (2FA) should be enabled for all users. Ensure that the checkbox next to Two-factor authentication (2FA) is selected.

The default setting for Two-factor grace period is 48 hours. This should be adjusted to a much lower value, such as 8 hours.

Ensure the checkbox next to Enable Admin Mode is selected so that Admin Mode is active. This requires users with Admin access to have to use additional authentication in order to perform administrative tasks, enforcing additional 2FA by the user.

In Email notification for unknown sign-ins, ensure that Enable email notification is selected. This sends an email to users when a sign-in occurs from an unrecognized location.

For more detailed information, see sign-in restrictions.

Integrations

  1. On the left sidebar, at the bottom, select Admin area.
  2. Select Settings > Integrations.

In general, as long as administrators control and monitor usage, integrations are fine in a hardened environment. Be cautious about integrations that allow for actions from an outside system that trigger actions and processes that typically require a level of access you would restrict or audit if performed by a local process or authenticated user.

Metrics and profiling

  1. On the left sidebar, at the bottom, select Admin area.
  2. Select Settings > Metrics and profiling.

The main focus for hardening is Usage statistics:

  • You should make sure Enable version check is selected. This checks to see if you are running the latest version of GitLab, and as new versions with new features and security patches come out frequently, this helps you stay up to date.

  • If your environment is isolated or one where your organizational requirements restrict data gathering and statistics reporting to a software vendor, you may have to disable the Enable service ping feature. For more information on what data is collected to help you make an informed decision, see service ping.

Network

  1. On the left sidebar, at the bottom, select Admin area.
  2. Select Settings > Network.

For any setting that enables rate limiting, make sure it is selected. Default values should be fine. Additionally there are numerous settings that enable access, and all of these should be cleared.

After you’ve made these adjustments you can fine tune the system to meet performance and user needs, which may require disabling and adjusting rate limits or enabling accesses. Here are a few notables to keep in mind:

  • In Outbound requests, if you need to open up access to a limited number of systems, you can limit access to just those systems by specifying IP address or hostname. Also in this section, make sure you’ve selected Enforce DNS rebinding attack protection if you’re allowing any access at all.

  • Under Notes rate limit and Users API rate limit you can exclude specific users from those limits if needed.