Incorrect permissions for home directories

[Boris Kolar]

Home directories (home/<username> created by installer , /root) have 0755 permissions, which allows users to read other user's files and directories. Permissions should be set to 0700.

[Martin Pitt (pitti)]

This is an explicit design decision to make sharing files easy (and feasible at all for non-techy users). Files with sensible data (emails, SSH/GPG keys, etc.) are created with appropriate privileges anyway.

[Boris Kolar (boris-kolar)]

It's a terrible design decision. Making saring easy is good, sharing by default is not. Please also see #67128 for arguments, why this design decision needs to be changed (most notably: it violated "security by default" principle).

I don't want to start a fight here, because it's easy for me to chmod 0700 for desired behaviour. But novice users may be unaware that their home directories are shared by default. This can cause serious leaks of sensible data (including passwords, or bank account info) which users have put in their home directories. I strongly believe that sharing should require explicit action (perhaps with a check box in some GUI configuration program), which indeed makes things a bit more complex, but not necessarily too complex for novice users.

In any case, making sharing explicit (and therefore more difficult) is better than allowing possibility of catastrophic private data leaks.