From 47b5b441395921e9f8e9982bb3f560e5db5a67bc Mon Sep 17 00:00:00 2001 From: Jacob Vosmaer Date: Tue, 12 Jul 2016 17:22:10 +0200 Subject: Defend against 'Host' header injection Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/17877 . This change adds 'defense in depth' against 'Host' HTTP header injection. It affects normal users in the following way. Suppose your GitLab server has IP address 1.2.3.4 and hostname gitlab.example.com. Currently, if you enter 1.2.3.4 in your browser, you get redirected to 1.2.3.4/users/sign_in. After this change, you get redirected from 1.2.3.4 to gitlab.example.com/users/sign_in. This is because the address you typed in the address bar of your browser ('1.2.3.4'), which gets stored in the 'Host' header, is now being overwritten to 'gitlab.example.com' in NGINX. In this change we also make NGINX clear the 'X-Forwarded-Host' header because Ruby on Rails also uses that header the same wayas the 'Host' header. We think that for most GitLab servers this is the right behavior, and if not then administrators can change this behavior themselves at the NGINX level. --- lib/support/nginx/gitlab | 7 ++++++- lib/support/nginx/gitlab-ssl | 7 ++++++- 2 files changed, 12 insertions(+), 2 deletions(-) (limited to 'lib/support/nginx') diff --git a/lib/support/nginx/gitlab b/lib/support/nginx/gitlab index d521de28e8a..4a4892a2e07 100644 --- a/lib/support/nginx/gitlab +++ b/lib/support/nginx/gitlab @@ -49,7 +49,12 @@ server { proxy_http_version 1.1; - proxy_set_header Host $http_host; + ## By overwriting Host and clearing X-Forwarded-Host we ensure that + ## internal HTTP redirects generated by GitLab always send users to + ## YOUR_SERVER_FQDN. + proxy_set_header Host YOUR_SERVER_FQDN; + proxy_set_header X-Forwarded-Host ""; + proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header X-Forwarded-Proto $scheme; diff --git a/lib/support/nginx/gitlab-ssl b/lib/support/nginx/gitlab-ssl index bf014b56cf6..0b93d7f292f 100644 --- a/lib/support/nginx/gitlab-ssl +++ b/lib/support/nginx/gitlab-ssl @@ -93,7 +93,12 @@ server { proxy_http_version 1.1; - proxy_set_header Host $http_host; + ## By overwriting Host and clearing X-Forwarded-Host we ensure that + ## internal HTTP redirects generated by GitLab always send users to + ## YOUR_SERVER_FQDN. + proxy_set_header Host YOUR_SERVER_FQDN; + proxy_set_header X-Forwarded-Host ""; + proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-Ssl on; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; -- cgit v1.2.1