[SSSD-users] AD user is granted access when it should be denied
Hi,
I am running sssd-1.16.4-21.el7.x86_64 (from CR repo) on a CentOS 7 client. I authenticate
to AD 2016, and control access to servers using GPO. For some reason, a completely
unprivileged user in AD is allowed to login, and I'd like to understand why.
Here's a sanitized sssd.conf:
[sssd]
domains = prd.domain.com
config_file_version = 2
services = nss, pam, sudo
full_name_format = %1$s
default_domain_suffix = prd.domain.com
[domain/prd.domain.com]
debug_level = 9
ad_domain = prd.domain.com
ad_site = XX1
ad_server = dc000.prd.domain.com, dc001.prd.domain.com
krb5_realm = PRD.DOMAIN.COM
realmd_tags = manages-system joined-with-samba
cache_credentials = false
id_provider = ad
krb5_store_password_if_offline = True
default_shell = /bin/bash
ldap_id_mapping = true
use_fully_qualified_names = True
fallback_homedir = /home/%u
access_provider = ad
ldap_sudo_search_base = DC=domain,DC=com
entry_cache_sudo_timeout = 10
enumerate = true
dyndns_update = false
ad_gpo_access_control = enforcing
ldap_idmap_default_domain_sid = S-1-5-21-6607581186-1994368826-2594857426
ldap_idmap_default_domain = prd.domain.com
ad_gpo_implicit_deny = true
auto_private_groups = true
ad_gpo_ignore_unreadable = true
When I try to SSH to the client using my unprivileged user, I am getting the following
output from the SSSD debug:
[sysdb_gpo_get_gpo_result_setting] (0x0400): key [SeDenyRemoteInteractiveLogonRight] value
[*S-1-5-32-546]
[ad_gpo_access_check] (0x0400): RESULTANT POLICY:
[ad_gpo_access_check] (0x0400): gpo_map_type: Remote Interactive
[ad_gpo_access_check] (0x0400): allowed_size = 0
[ad_gpo_access_check] (0x0400): denied_size = 1
[ad_gpo_access_check] (0x0400): denied_sids[0] = S-1-5-32-546
... snip ...
[ad_gpo_access_check] (0x0400): CURRENT USER:
[ad_gpo_access_check] (0x0400): user_sid =
S-1-5-21-6607581186-1994368826-2594857426-2570
[ad_gpo_access_check] (0x0400): group_sids[0] =
S-1-5-21-6607581186-1994368826-2594857426-513
[ad_gpo_access_check] (0x0400): group_sids[1] = S-1-5-11
[ad_gpo_access_check] (0x0400): POLICY DECISION:
[ad_gpo_access_check] (0x0400): access_granted = 1
[ad_gpo_access_check] (0x0400): access_denied = 0
[ad_gpo_access_done] (0x0400): GPO-based access control successful.
I'm trying to understand why this user is being granted access. I find it especially
confusing as there is clearly one deny sid and no allow sids detected. The wanted
behaviour is that the user should be denied access as long as I've not explicitly
allowed it in AD.
Thanks!