dvershinin / gixy

NGINX configuration static analyzer

GIXY

Overview

Gixy is a tool to analyze Nginx configuration. The main goal of Gixy is to prevent security misconfiguration and automate flaw detection.

Currently supported Python versions are 3.6, 3.7, 3.8 and 3.9.

Disclaimer: Gixy is well tested only on GNU/Linux, other OSs may have some issues.

What it can do

Right now Gixy can find:

• [ssrf] Server Side Request Forgery
• [http_splitting] HTTP Splitting
• [origins] Problems with referrer/origin validation
• [add_header_redefinition] Redefining of response headers by "add_header" directive
• [host_spoofing] Request's Host header forgery
• [valid_referers] none in valid_referers
• [add_header_multiline] Multiline response headers
• [alias_traversal] Path traversal via misconfigured alias
• [if_is_evil] If is evil when used in location context
• [allow_without_deny] Allow specified without deny
• [add_header_content_type] Setting Content-Type via add_header
• [resolver_external] Using external DNS nameservers
• [version_disclosure] Using insecure values for server_tokens

You can find things that Gixy is learning to detect at Issues labeled with "new plugin"

Installation

CentOS/RHEL and other RPM-based systems

yum -y install https://extras.getpagespeed.com/release-latest.rpm
yum -y install gixy

Other systems

Gixy is distributed on PyPI. The best way to install it is with pip:

pip install gixy-ng

Run Gixy and check results:

gixy

Usage

By default, Gixy will try to analyze NGINX configuration placed in /etc/nginx/nginx.conf.

But you can always specify the needed path:

$ gixy /etc/nginx/nginx.conf

==================== Results ===================

Problem: [http_splitting] Possible HTTP-Splitting vulnerability.
Description: Using variables that can contain "\n" may lead to http injection.
Additional info: https://github.com/dvershinin/gixy/blob/master/docs/ru/plugins/httpsplitting.md
Reason: At least variable "$action" can contain "\n"
Pseudo config:
include /etc/nginx/sites/default.conf;

	server {

		location ~ /v1/((?<action>[^.]*)\.json)?$ {
			add_header X-Action $action;
		}
	}


==================== Summary ===================
Total issues:
    Unspecified: 0
    Low: 0
    Medium: 0
    High: 1

Or skip some tests:

$ gixy --skips http_splitting /etc/nginx/nginx.conf

==================== Results ===================
No issues found.

==================== Summary ===================
Total issues:
    Unspecified: 0
    Low: 0
    Medium: 0
    High: 0

Or something else, you can find all other gixy arguments with the help command: gixy --help

You can also make gixy use pipes (stdin), like so:

echo "resolver 1.1.1.1;" | gixy -

Docker usage

Gixy is available as a Docker image from the Docker hub. To use it, mount the configuration that you want to analyse as a volume and provide the path to the configuration file when running the Gixy image.

$ docker run --rm -v `pwd`/nginx.conf:/etc/nginx/conf/nginx.conf getpagespeed/gixy /etc/nginx/conf/nginx.conf

If you have an image that already contains your nginx configuration, you can share the configuration with the Gixy container as a volume.

$  docker run --rm --name nginx -d -v /etc/nginx
nginx:alpinef68f2833e986ae69c0a5375f9980dc7a70684a6c233a9535c2a837189f14e905

$  docker run --rm --volumes-from nginx dvershinin/gixy /etc/nginx/nginx.conf

==================== Results ===================
No issues found.

==================== Summary ===================
Total issues:
    Unspecified: 0
    Low: 0
    Medium: 0
    High: 0

Contributing

Contributions to Gixy are always welcome! You can help us in different ways:

• Open an issue with suggestions for improvements and errors you're facing;
• Fork this repository and submit a pull request;
• Improve the documentation.

Code guidelines:

• Python code style should follow pep8 standards whenever possible;
• Pull requests with new plugins must have unit tests for it.