samba: fix CVE-2023-4091

A vulnerability was discovered in Samba, where the flaw allows SMB clients to
truncate files, even with read-only permissions when the Samba VFS module
"acl_xattr" is configured with "acl_xattr:ignore system acls = yes". The SMB
protocol allows opening files when the client requests read-only access but
then implicitly truncates the opened file to 0 bytes if the client specifies
a separate OVERWRITE create disposition request. The issue arises in configurations
that bypass kernel file system permissions checks, relying solely on Samba's permissions.

References:
https://nvd.nist.gov/vuln/detail/CVE-2023-4091

Fix is patched to the function call smbd_check_access_rights_fsp() of open_file(),
But in samba_4.14.14 smbd_check_access_rights() is used, from samba_4.15.0 onwards
smbd_check_access_rights() was replaced with smbd_check_access_rights_fsp() and
samba_4.14.14 is still vulnerable through smbd_check_access_rights().

Ref:
https://github.com/samba-team/samba/commit/3f61369d153419158c0f223e6f81c0bb07275833
https://github.com/samba-team/samba/commit/26dc10bdb2cff3eece4a2874931b4058f9f87d68

Signed-off-by: Archana Polampalli <archana.polampalli@windriver.com>
Signed-off-by: Armin Kuster <akuster808@gmail.com>

0 files changed, 0 insertions, 0 deletions