The open_envvar function in xdg-open in xdg-utils before 1.1.3 does not validate strings before launching the program specified by the BROWSER environment variable, which might allow remote attackers to conduct argument-injection attacks via a crafted URL, as demonstrated by %s in this environment variable.
Upstream bug report:
Created xdg-utils tracking bugs for this issue:
Affects: fedora-all [bug 1578768]
This issue did not affect the versions of xdg-utils as shipped with Red Hat Enterprise Linux 6 and 7.