Information disclosure in Samba

1) Improper access control

EUVDB-ID: #VU83535

Risk: Low

CVSSv3.1: 3.8 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2018-14628

CWE-ID: CWE-284 - Improper Access Control

Exploit availability: No

Description

The vulnerability allows a remote user to gain access to sensitive information.

The vulnerability exists due to improper access restrictions when Samba is an Active Directory Domain Controller. When a domain was provisioned with an unpatched Samba version, the ntSecurityDescriptor is simply inherited from Domain/Partition-HEAD-Object instead of being very strict (as on a Windows provisioned domain). This means also non privileged users can use the LDAP_SERVER_SHOW_DELETED_OID control in order to view, the names and preserved attributes of deleted objects.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Samba: 4.0.0 - 4.19.2

External links

http://bugzilla.samba.org/show_bug.cgi?id=13595
http://bugzilla.redhat.com/show_bug.cgi?id=1625445
http://www.samba.org/samba/security/CVE-2018-14628.html
http://www.samba.org/samba/history/samba-4.19.3.html

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.