[SSSD-users] session management by sssd (when using LDAP as an authentication and authorization server)
Hello,
I installed and configured SSSD with LDAP server OUD (Oracle Unified Directory).
Everything works fine so far, except for one thing which I consider as a vulnerability.
I just found out that there is a potential security hole which is the old session of a
user who lost his authorization.
Generic example:
User1 has to belong to the LDAP group sshUsers which is configured as an access filter on
the SSSD client in order to be authorized (after the successfull authentication) for
access to the remote linux machine, where the SSSD client is installed.
User1 is a member of the LDAP group sshUsers and logs in to the remote linux machine.
After the successfull login of the User1 to the remote linux machine, its membership in
the LDAP group sshUsers is removed i.e. User1 looses it authorization to access the remote
linux machine.
What happens as a result is:
1. The active ssh connection od User1 to the remote linux machine which was established
before he lost his authorization is still active!!
2. User1 (after he lost his authorization) can not login to the remote linux machine
anymore - this is okay.
Security hole - explained in 1.
Can you please explain to me if there is a possiblity for SSSD to manage the sessions, how
to do that? If this is not possible (whn using OUD) should it be proposed as a bug?
Other than that, how is session managed on the OS layer?
Thank you!
BR,
Hristina