The vulnerability, tracked as CVE-2019-0211, affects Apache web server releases for Unix systems only, from 2.4.17 to 2.4.38, and was fixed this week with the release of version 2.4.39.

In this case, the issue affects only version 2.4.49 of Apache’s open-source web server, which offers cross-platform operability with all modern operating systems, including UNIX and Windows.

Apache HTTP Server is the second most widely used web server on the internet behind Nginx, according to W3Techs, which estimates it's used by 31.4% of the world's websites.