1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
|
---
type: reference, howto
---
# Rack Attack initializer
## Overview
[Rack Attack](https://github.com/kickstarter/rack-attack), also known as Rack::Attack, is a Ruby gem
that is meant to protect GitLab with the ability to customize throttling and
to block user IP addresses.
You can prevent brute-force passwords attacks, scrapers, or any other offenders
by throttling requests from IP addresses that are making large volumes of requests.
If you find throttling is not enough to protect you against abusive clients,
Rack Attack offers IP whitelisting, blacklisting, Fail2ban style filtering, and
tracking.
For more information on how to use these options see the [Rack Attack README](https://github.com/kickstarter/rack-attack/blob/master/README.md).
NOTE: **Note:** See
[User and IP rate limits](../user/admin_area/settings/user_and_ip_rate_limits.md)
for simpler limits that are configured in the UI.
NOTE: **Note:** Starting with GitLab 11.2, Rack Attack is disabled by default. If your
instance is not exposed to the public internet, it is recommended that you leave
Rack Attack disabled.
## Behavior
If set up as described in the [Settings](#settings) section below, two behaviors
will be enabled:
- Protected paths will be throttled.
- Failed authentications for Git and container registry requests will trigger a temporary IP ban.
### Protected paths throttle
GitLab responds with HTTP status code `429` to POST requests at protected paths
that exceed 10 requests per minute per IP address.
By default, protected paths are:
```ruby
default['gitlab']['gitlab-rails']['rack_attack_protected_paths'] = [
'/users/password',
'/users/sign_in',
'/api/#{API::API.version}/session.json',
'/api/#{API::API.version}/session',
'/users',
'/users/confirmation',
'/unsubscribes/',
'/import/github/personal_access_token'
]
```
This header is included in responses to blocked requests:
```
Retry-After: 60
```
For example, the following are limited to a maximum 10 requests per minute:
- User sign-in
- User sign-up (if enabled)
- User password reset
After 10 requests, the client must wait a minute before it can
try again.
### Git and container registry failed authentication ban
GitLab responds with HTTP status code `403` for 1 hour, if 30 failed
authentication requests were received in a 3-minute period from a single IP address.
This applies only to Git requests and container registry (`/jwt/auth`) requests
(combined).
This limit:
- Is reset by requests that authenticate successfully. For example, 29
failed authentication requests followed by 1 successful request, followed by 29
more failed authentication requests would not trigger a ban.
- Does not apply to JWT requests authenticated by `gitlab-ci-token`.
No response headers are provided.
## Settings
**Omnibus GitLab**
1. Open `/etc/gitlab/gitlab.rb` with your editor
1. Add the following:
```ruby
gitlab_rails['rack_attack_git_basic_auth'] = {
'enabled' => true,
'ip_whitelist' => ["127.0.0.1"],
'maxretry' => 10, # Limit the number of Git HTTP authentication attempts per IP
'findtime' => 60, # Reset the auth attempt counter per IP after 60 seconds
'bantime' => 3600 # Ban an IP for one hour (3600s) after too many auth attempts
}
```
1. Reconfigure GitLab:
```
sudo gitlab-ctl reconfigure
```
The following settings can be configured:
- `enabled`: By default this is set to `false`. Set this to `true` to enable Rack Attack.
- `ip_whitelist`: Whitelist any IPs from being blocked. They must be formatted as strings within a Ruby array.
CIDR notation is supported in GitLab v12.1 and up.
For example, `["127.0.0.1", "127.0.0.2", "127.0.0.3", "192.168.0.1/24"]`.
- `maxretry`: The maximum amount of times a request can be made in the
specified time.
- `findtime`: The maximum amount of time that failed requests can count against an IP
before it's blacklisted (in seconds).
- `bantime`: The total amount of time that a blacklisted IP will be blocked (in
seconds).
**Installations from source**
These settings can be found in `config/initializers/rack_attack.rb`. If you are
missing `config/initializers/rack_attack.rb`, the following steps need to be
taken in order to enable protection for your GitLab instance:
1. In `config/application.rb` find and uncomment the following line:
```ruby
config.middleware.use Rack::Attack
```
1. Copy `config/initializers/rack_attack.rb.example` to `config/initializers/rack_attack.rb`
1. Open `config/initializers/rack_attack.rb`, review the
`paths_to_be_protected`, and add any other path you need protecting
1. Restart GitLab:
```sh
sudo service gitlab restart
```
If you want more restrictive/relaxed throttle rules, edit
`config/initializers/rack_attack.rb` and change the `limit` or `period` values.
For example, more relaxed throttle rules will be if you set
`limit: 3` and `period: 1.seconds` (this will allow 3 requests per second).
You can also add other paths to the protected list by adding to `paths_to_be_protected`
variable. If you change any of these settings you must restart your
GitLab instance.
## Remove blocked IPs from Rack Attack via Redis
In case you want to remove a blocked IP, follow these steps:
1. Find the IPs that have been blocked in the production log:
```sh
grep "Rack_Attack" /var/log/gitlab/gitlab-rails/auth.log
```
1. Since the blacklist is stored in Redis, you need to open up `redis-cli`:
```sh
/opt/gitlab/embedded/bin/redis-cli -s /var/opt/gitlab/redis/redis.socket
```
1. You can remove the block using the following syntax, replacing `<ip>` with
the actual IP that is blacklisted:
```
del cache:gitlab:rack::attack:allow2ban:ban:<ip>
```
1. Confirm that the key with the IP no longer shows up:
```
keys *rack::attack*
```
1. Optionally, add the IP to the whitelist to prevent it from being blacklisted
again (see [settings](#settings)).
## Troubleshooting
### Rack attack is blacklisting the load balancer
Rack Attack may block your load balancer if all traffic appears to come from
the load balancer. In that case, you will need to:
1. [Configure `nginx[real_ip_trusted_addresses]`](https://docs.gitlab.com/omnibus/settings/nginx.html#configuring-gitlab-trusted_proxies-and-the-nginx-real_ip-module).
This will keep users' IPs from being listed as the load balancer IPs.
1. Whitelist the load balancer's IP address(es) in the Rack Attack [settings](#settings).
1. Reconfigure GitLab:
```
sudo gitlab-ctl reconfigure
```
1. [Remove the block via Redis.](#remove-blocked-ips-from-rack-attack-via-redis)
|
