2 ms·

Why? Why don't you uninstall bash all-together? Most programs should be using '/bin/sh' and not bash.(IIRC Linux might have symlink between the two, which is a

by atmosx 12y ago

Why? Why don't you uninstall bash all-together? Most programs should be using '/bin/sh' and not bash.(IIRC Linux might have symlink between the two, which is awful) You could install zsh. You could add further security layers, harden your network-level access, monitor your logs and so forth. Security is a set of policies. If you think that there are users who have unauthorized access to your system or you run bash-enabled cgi scripts, well then disable them (you shouldn't be using those in first place anyway), lock-out unauthorized users, change your passwords, etc. The panic is for admins who handle systems with multiple users (universities, etc.) and offer (even restricted) shell access. For these guys might be hard to sleep at night, but for someone running a fileserver, shouldn't really make any diff.

rcthompson 12y ago
I don't have the time right now to figure out what the default shell is and whether Ubuntu supports switching it, and whether I have any custom scrips or some such that assume /bin/sh is bash. So the easiest thing to do is just disconnect it for now.
Karunamon 12y ago
>Most programs should be using '/bin/sh' and not bash. Why? There are some non-trivial things that you can do in bash but not sh (or dash)[1]. Remaining POSIX compatible by way of never adding additional features seems like a great way to never make any forward progress. [1]: http://mywiki.wooledge.org/Bashism http://mywiki.wooledge.org/Bashism
- atmosx 12y ago
  From FreeBSD manual page for 'sh': DESCRIPTION The sh utility is the standard command interpreter for the system. The current version of sh is close to the IEEE Std 1003.1 (“POSIX.1”) specification for the shell. It only supports features designated by POSIX,plus a few Berkeley extensions. [...] Again from FreeBSD manual for 'bash': DESCRIPTION Bash is an sh-compatible command language interpreter that executes commands read from the standard input or from a file. Bash also incorporates useful features from the Korn and C shells (ksh and csh). Bash is intended to be a conformant implementation of the Shell and Utilities portion of the IEEE POSIX specification (IEEE Standard 1003.1). Bash can be configured to be POSIX-conformant by default. These two shells are different and the reason that FreeBSD keeps '/bin/sh' is because it was designed to be secure and reliable instead of full-featured. Makes sense as a choice, it is aligned with the general UNIX philosophy: do one thing, do it good, keep it as simple as possible. Given the fact that the bug was found in bash, I guess it's just (another) win for this harsh philosophy that so many geeks seem to strongly embrace.

by atmosx 12y ago

rcthompson 12y ago

I don't have the time right now to figure out what the default shell is and whether Ubuntu supports switching it, and whether I have any custom scrips or some such that assume /bin/sh is bash. So the easiest thing to do is just disconnect it for now.

Karunamon 12y ago

>Most programs should be using '/bin/sh' and not bash. Why? There are some non-trivial things that you can do in bash but not sh (or dash)[1]. Remaining POSIX compatible by way of never adding additional features seems like a great way to never make any forward progress. [1]: http://mywiki.wooledge.org/Bashism http://mywiki.wooledge.org/Bashism

atmosx 12y ago
From FreeBSD manual page for 'sh': DESCRIPTION The sh utility is the standard command interpreter for the system. The current version of sh is close to the IEEE Std 1003.1 (“POSIX.1”) specification for the shell. It only supports features designated by POSIX,plus a few Berkeley extensions. [...] Again from FreeBSD manual for 'bash': DESCRIPTION Bash is an sh-compatible command language interpreter that executes commands read from the standard input or from a file. Bash also incorporates useful features from the Korn and C shells (ksh and csh). Bash is intended to be a conformant implementation of the Shell and Utilities portion of the IEEE POSIX specification (IEEE Standard 1003.1). Bash can be configured to be POSIX-conformant by default. These two shells are different and the reason that FreeBSD keeps '/bin/sh' is because it was designed to be secure and reliable instead of full-featured. Makes sense as a choice, it is aligned with the general UNIX philosophy: do one thing, do it good, keep it as simple as possible. Given the fact that the bug was found in bash, I guess it's just (another) win for this harsh philosophy that so many geeks seem to strongly embrace.