As per the upstream bug :
Samba 4.0 as an AD DC may provide authenticated users with write access to LDAP directory objects.
In AD, Access Control Entries can be assigned based on the objectClass of the object. If a user or a group the user is a member of has any access based on the objectClass, then that user has write access to that object.
Additionally, if a user has write access to any attribute on the object, they may have access to write to all attributes.
An important mitigation is that anonymous access is totally disabled by default. The second important mitigation is that normal users are typically only given the problematic per-objectClass right via the "pre-windows 2000 compatible access" group, and Samba 4.0.0 incorrectly does not make "authenticated users" part of this group.
NOTE: Only Fedora 17+ provide the Domain Controller components; Red Hat Enterprise Linux 6 does not provide the Domain Controller components in its samba4 package.
This was corrected in upstream version 4.0.1 .
Not vulnerable. This issue did not affect the versions of samba4 as shipped with Red Hat Enterprise Linux 6 as they did not include support for the Domain Controller components.
Only Fedora 16 and Fedora 17 are affected. Fedora 18 does not include Domain Controller components.
Created samba4 tracking bugs for this issue
Affects: fedora-all [bug 895636]
(In reply to comment #1)
> Only Fedora 16 and Fedora 17 are affected. Fedora 18 does not include Domain
> Controller components.
Thank you for the clarification!
samba4-4.0.0-59alpha18.fc17 has been pushed to the Fedora 17 stable repository. If problems still persist, please make note of it in this bug report.