after installing firefox many of the permissions are set to 777, allowing anyone on the system to change the contents of the (executable) files. this first occured in the 0.9 release (in the tar.gz release as well as in the installer). the problem (or is it called a feature now?) still exists in the latest release v0.9.3. the problem was reported on bugzilla long long time ago by myself and others. lunanova:/tmp# tar xzf firefox-0.9.3-i686-linux-gtk2+xft-installer.tar.gz lunanova:/tmp# cd firefox-installer/ lunanova:/tmp/firefox-installer# ./firefox-installer # ... installing to /tmp/firefox-0.9.3 lunanova:/tmp/firefox-installer# exit max@lunanova:~$ cd /tmp/firefox-0.9.3 max@lunanova:/tmp/firefox-0.9.3$ echo 'echo "oops"' > run-mozilla.sh max@lunanova:/tmp/firefox-0.9.3$ ./firefox oops max@lunanova:/tmp/firefox-0.9.3$ ls -l total 12676 drwxr-xr-x 4 root root 4096 Sep 13 21:02 chrome drwxr-xr-x 3 root root 4096 Sep 13 21:02 components drwxr-xr-x 5 root root 4096 Sep 13 21:02 defaults drwxr-xr-x 2 root root 4096 Sep 13 21:02 extensions -rwxr-xr-x 1 root root 4775 Aug 3 14:14 firefox -rwxr-xr-x 1 root root 9758932 Aug 3 14:14 firefox-bin drwxr-xr-x 2 root root 4096 Sep 13 21:02 greprefs -rw-r--r-- 1 root root 29364 Sep 13 21:02 install.log -rwxrwxrwx 1 root root 441204 Aug 3 14:14 libmozjs.so -rwxrwxrwx 1 root root 177164 Aug 3 14:14 libnspr4.so -rwxrwxrwx 1 root root 405372 Aug 3 14:14 libnss3.so -rwxrwxrwx 1 root root 170068 Aug 3 14:14 libnssckbi.so -rwxrwxrwx 1 root root 15272 Aug 3 14:14 libplc4.so -rwxrwxrwx 1 root root 8240 Aug 3 14:14 libplds4.so -rwxrwxrwx 1 root root 134188 Aug 3 14:14 libsmime3.so -rw-rw-rw- 1 root root 476 Aug 3 14:14 libsoftokn3.chk -rwxrwxrwx 1 root root 419824 Aug 3 14:14 libsoftokn3.so -rwxrwxrwx 1 root root 125376 Aug 3 14:14 libssl3.so -rwxrwxrwx 1 root root 661232 Aug 3 14:14 libxpcom.so -rwxrwxrwx 1 root root 94888 Aug 3 14:14 libxpcom_compat.so -rwxrwxrwx 1 root root 7736 Aug 3 14:14 libxpistub.so -rwxrwxrwx 1 root root 236615 Aug 3 14:14 mozilla-xremote-client drwxr-xr-x 2 root root 4096 Sep 13 21:02 plugins -rw-r--r-- 1 root root 335 Sep 13 21:02 registry drwxr-xr-x 7 root root 4096 Sep 13 21:02 res -rwxrwxrwx 1 root root 12 Sep 13 21:03 run-mozilla.sh drwxr-xr-x 2 root root 4096 Sep 13 21:02 searchplugins -rwxrwxrwx 1 root root 147500 Aug 3 14:14 xpicleanup .. subdirs dont look much better.