Permissions, Privileges, and Access Controls in Samba

1) Permissions, Privileges, and Access Controls

EUVDB-ID: #VU32347

Risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2015-5252

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

The vulnerability allows a remote non-authenticated attacker to read and manipulate data.

vfs.c in smbd in Samba 3.x and 4.x before 4.1.22, 4.2.x before 4.2.7, and 4.3.x before 4.3.3, when share names with certain substring relationships exist, allows remote attackers to bypass intended file-access restrictions via a symlink that points outside of a share.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Samba: 4.1.0 - 4.3.2

CPE2.3

• cpe:2.3:a:samba:samba:4.1.0:*:*:*:*:*:*:*
• cpe:2.3:a:samba:samba:4.1.1:*:*:*:*:*:*:*
• cpe:2.3:a:samba:samba:4.1.2:*:*:*:*:*:*:*
• cpe:2.3:a:samba:samba:4.1.3:*:*:*:*:*:*:*
• cpe:2.3:a:samba:samba:4.1.4:*:*:*:*:*:*:*
• cpe:2.3:a:samba:samba:4.1.5:*:*:*:*:*:*:*
• cpe:2.3:a:samba:samba:4.1.6:*:*:*:*:*:*:*
• cpe:2.3:a:samba:samba:4.1.7:*:*:*:*:*:*:*
• cpe:2.3:a:samba:samba:4.1.8:*:*:*:*:*:*:*
• cpe:2.3:a:samba:samba:4.1.9:*:*:*:*:*:*:*

External links

https://lists.fedoraproject.org/pipermail/package-announce/2015-December/174076.html
https://lists.fedoraproject.org/pipermail/package-announce/2015-December/174391.html
https://lists.opensuse.org/opensuse-security-announce/2015-12/msg00019.html
https://lists.opensuse.org/opensuse-security-announce/2015-12/msg00020.html
https://lists.opensuse.org/opensuse-security-announce/2015-12/msg00032.html
https://lists.opensuse.org/opensuse-security-announce/2015-12/msg00033.html
https://lists.opensuse.org/opensuse-security-announce/2016-01/msg00002.html
https://lists.opensuse.org/opensuse-security-announce/2016-01/msg00017.html
https://lists.opensuse.org/opensuse-security-announce/2016-04/msg00042.html
https://lists.opensuse.org/opensuse-security-announce/2016-04/msg00046.html
https://lists.opensuse.org/opensuse-security-announce/2016-04/msg00047.html
https://lists.opensuse.org/opensuse-security-announce/2016-04/msg00048.html
https://www.debian.org/security/2016/dsa-3433
https://www.oracle.com/technetwork/topics/security/bulletinjan2016-2867206.html
https://www.oracle.com/technetwork/topics/security/linuxbulletinjan2016-2867209.html
https://www.securityfocus.com/bid/79733
https://www.securitytracker.com/id/1034493
https://www.ubuntu.com/usn/USN-2855-1
https://www.ubuntu.com/usn/USN-2855-2
https://bugzilla.redhat.com/show_bug.cgi?id=1290288
https://git.samba.org/?p=samba.git;a=commit;h=4278ef25f64d5fdbf432ff1534e275416ec9561e
https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05115993
https://security.gentoo.org/glsa/201612-47
https://www.samba.org/samba/security/CVE-2015-5252.html

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker 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.