Upstream bug: https://bugzilla.mozilla.org/show_bug.cgi?id=307185 The URL passed to mozilla on the command line does not properly escape dangerous characters before handing the URL to the shell.
This issue should also affect RHEL2.1 and RHEL3
Note this is rated important not critical - a user would have to be tricked into clicking on a link in an external application that contains the backtick characters.
After investigating the shell scripts Red Hat ships, we have determined that our Mozilla pakcages are not vulnerable to this issue.