Comment 6 for bug 906550

I have noticed that ecryptfs-utils is the default program used by the
Ubuntu distributions for home folder encryption since version 10.04.
In this case, the wrapping key is generated from the user password
using the hash function SHA-512. As mentioned previously, the wrapping
key is hashed with the default fixed salt and stored in the
"wrapped-passphrase" file. What’s interesting with Ubuntu
installations, since the salt is fixed, time-memory trade-off (rainbow
tables, etc.) can apply, as well as bulk dictionary attacks to crack
user passwords of Ubuntu installations when the home folder encryption
is activated.
I think a CVE should be open for this issue. I will work on this bug and
propose a patch soon.