#VU47990 Permissions, Privileges, and Access Controls in Samba


Published: 2020-10-29

Vulnerability identifier: #VU47990

Vulnerability 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-2020-14318

CWE-ID: CWE-264

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Samba
Server applications / Directory software, identity management

Vendor: Samba

Description

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

The vulnerability exists due to the way "ChangeNotify" concept for SMB1/2/3 protocols was implemented in Samba. A missing permissions check on a directory handle requesting ChangeNotify means that a client with a directory handle open only for FILE_READ_ATTRIBUTES (minimal access rights) could be used to obtain change notify replies from the server. These replies contain information that should not be available to directory handles open for FILE_READ_ATTRIBUTE only. A local unprivileged user can abuse this lack of permissions check to obtain information about file changes.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Samba: 4.13.0, 4.12.0 - 4.12.8, 4.11.0 - 4.11.14, 4.10.0 - 4.10.18, 4.9.0 - 4.9.18, 4.8.0 - 4.8.12, 4.7.0 - 4.7.12, 4.6.0 - 4.6.16, 4.5.0 - 4.5.16, 4.4.0 - 4.4.16, 4.3.0 - 4.3.13, 4.2.0 - 4.2.14, 4.1.0 - 4.1.23, 4.0.0 - 4.0.26, 3.6.0 - 3.6.25


External links
http://www.samba.org/samba/security/CVE-2020-14318.html


Q & A

Can this vulnerability be exploited remotely?

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

Is there known malware, which exploits this vulnerability?

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


Latest bulletins with this vulnerability