I don't know if it is a security bug or not. When I use sysrc today, the error operations emptied my /etc/rc.conf, that's a small disaster, because my /etc/rc.conf is updated day by day, but now, it is empty. First, change your default root shell to sh/ksh or their derived shell. (I have tested, csh will not trigger that bug). Second, backup /etc/rc.conf to any other place. Then do the following commands: ------------------------------------------------------------------------ # sysrc something_enable="NO" # sysrc something_enable="YES> "awk: newline in string YES ... at source line 1 something_enable: NO -> YES ------------------------------------------------------------------------ Now see what is inside /etc/rc.conf ? Everything is empty! only one thing in it: ------------------------------------------------------------------------ something_enable="YES " ------------------------------------------------------------------------ Sent with [ProtonMail](https://protonmail.com) Secure Email.
To my knowledge, it is not recommended to change default shell. As for rest I will leave to other experts. https://docs.freebsd.org/en/articles/linux-users/#shells Regards, Mario> On 30 May 2021, at 06:36, Fas Xmut via freebsd-security <freebsd-security at freebsd.org> wrote: > > ?I don't know if it is a security bug or not. When I use sysrc today, the error operations emptied my /etc/rc.conf, that's a small disaster, because my /etc/rc.conf is updated day by day, but now, it is empty. > > First, change your default root shell to sh/ksh or their derived shell. (I have tested, csh will not trigger that bug). > > Second, backup /etc/rc.conf to any other place. > > Then do the following commands: > > ------------------------------------------------------------------------ > # sysrc something_enable="NO" > # sysrc something_enable="YES >> " > awk: newline in string YES > ... at source line 1 > something_enable: NO -> YES > ------------------------------------------------------------------------ > > Now see what is inside /etc/rc.conf ? Everything is empty! only one thing in it: > > ------------------------------------------------------------------------ > something_enable="YES > " > ------------------------------------------------------------------------ > > Sent with [ProtonMail](https://protonmail.com) Secure Email. > _______________________________________________ > freebsd-security at freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-security > To unsubscribe, send any mail to "freebsd-security-unsubscribe at freebsd.org"
30.05.2021 11:36, Fas Xmut via freebsd-security wrote:> I don't know if it is a security bug or not. When I use sysrc today, the error operations emptied my /etc/rc.conf, that's a small disaster, because my /etc/rc.conf is updated day by day, but now, it is empty. > > First, change your default root shell to sh/ksh or their derived shell. (I have tested, csh will not trigger that bug). > > Second, backup /etc/rc.conf to any other place. > > Then do the following commands: > > ------------------------------------------------------------------------ > # sysrc something_enable="NO" > # sysrc something_enable="YES >> " > awk: newline in string YES > ... at source line 1 > something_enable: NO -> YES > ------------------------------------------------------------------------ > > Now see what is inside /etc/rc.conf ? Everything is empty! only one thing in it: > > ------------------------------------------------------------------------ > something_enable="YES > " > ------------------------------------------------------------------------What is your FreeBSD version?