Gentoo Linux Security Advisory GLSA 200512-10 – Peter Zelezny discovered that the shell script used to launch Opera parses shell commands that are enclosed within backticks in the URL provided via the command line. Versions less than 8.51 are affected.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/42555/glsa-200512-10.txt
Source: https://packetstormsecurity.com/files/42555/Gentoo-Linux-Security-Advisory-200512-10.html