As news came out today that there’s a vulnerability on HTTP_PROXY infecting CGI application on PHP, Python, Go and others known as httpoxy. The Production Leadership Team and the Joomla! Project wants to raise awareness of this to it’s users.
The Joomla! core itself is not affected in any way by this vulnerability, but third party extensions using specific PHP libraries might be. As of now we have no further information on which third parties extensions may use any affected libraries, so we ask all of our users to check with their extension providers to see if their extension might be affected. The HTTP protocol is used to make requests for information on the Internet, such as to load a web page, image file, or data from a RESTful API.
More information on the vulnerability can be found at : https://httpoxy.org/
For example we know the Guzzle library (a very popular one) is affected, therefore it’s recommended to update the library as soon as possible. For this specific library you can find a fix on github at the following link : https://github.com/guzzle/guzzle/commit/9d521b23146cb6cedd772770a2617fd6cbdb1596 or via Composer.
If you are not sure what libraries are used by your Third Party extension providers, please contact them. If you see updates in the next few days from these developers, please apply them.