CVE-2015-8467: High severity samba vulnerability
As per samba upstream advisory:
Samba, operating as an AD DC, is sometimes operated in a domain with a mix of Samba and Windows Active Directory Domain Controllers.
All versions of Samba from 4.0.0 to 4.3.2 inclusive, when deployed as an AD DC in the same domain with Windows DCs, could be used to override the protection against the MS15-096 / CVE-2015-2535 security issue in Windows.
Prior to MS16-096 it was possible to bypass the quota of machine accounts a non-administrative user could create. Pure Samba domains are not impacted, as Samba does not implement the SeMachineAccountPrivilege functionality to allow non-administrator users to create new computer objects.
The following mitigation was suggested by upstream:
Only users with SeMachineAccountPrivilege can exploit this issue in Windows, removing this privilege from "Authenticated Users" can provide a mitigation.
Other sources
The samldbcheckuseraccountcontrolacl function in dsdb/samdb/ldbmodules/samldb.c in Samba 4.x before 4.1.22, 4.2.x before 4.2.7, and 4.3.x before 4.3.3 does not properly check for administrative privileges during creation of machine accounts, which allows remote authenticated users to bypass intended access restrictions by leveraging the existence of a domain with both a Samba DC and a Windows DC, a similar issue to CVE-2015-2535.
— MITRE
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2015-8467?
CVE-2015-8467 is classified as a medium severity vulnerability.
How do I fix CVE-2015-8467?
To fix CVE-2015-8467, upgrade Samba to a version higher than 4.3.3.
Which versions of Samba are affected by CVE-2015-8467?
All versions of Samba from 4.0.0 to 4.3.2 are affected by CVE-2015-8467.
What systems are vulnerable to CVE-2015-8467?
Samba deployed as an Active Directory Domain Controller in mixed environments with Windows Domain Controllers are vulnerable to CVE-2015-8467.
Is CVE-2015-8467 related to Active Directory?
Yes, CVE-2015-8467 specifically affects Samba acting as an Active Directory Domain Controller.