Input validation error in Samba

1) Input validation error

EUVDB-ID: #VU32348

Risk: Medium

CVSSv4.0: 1.7 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2015-5296

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

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

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 supports connections that are encrypted but unsigned, which allows man-in-the-middle attackers to conduct encrypted-to-unencrypted downgrade attacks by modifying the client-server data stream, related to clidfs.c, libsmb_server.c, and smbXcli_base.c.

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:4.1.21:*:*:*:*:*:*:*
• cpe:2.3:a:samba:samba:4.2.6:*:*:*:*:*:*:*
• cpe:2.3:a:samba:samba:4.3.2:*:*:*:*:*:*:*

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/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/79732
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=1290292
https://git.samba.org/?p=samba.git;a=commit;h=1ba49b8f389eda3414b14410c7fbcb4041ca06b1
https://git.samba.org/?p=samba.git;a=commit;h=a819d2b440aafa3138d95ff6e8b824da885a70e9
https://git.samba.org/?p=samba.git;a=commit;h=d724f835acb9f4886c0001af32cd325dbbf1f895
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-2015-5296.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.