製品・ソフトウェアに関する情報

JVN脆弱性詳細

Samba における暗号化から非暗号化するダウングレード攻撃を実行される脆弱性

Title	Samba における暗号化から非暗号化するダウングレード攻撃を実行される脆弱性
Summary	Samba は、暗号化されているが未署名の接続をサポートするため、暗号化から非暗号化する (encrypted-to-unencrypted) ダウングレード攻撃を実行される脆弱性が存在します。
Possible impacts	中間者攻撃 (man-in-the-middle attack) により、クライアント-サーバデータストリームを変更されることで、暗号化から非暗号化する (encrypted-to-unencrypted) ダウングレード攻撃を実行される可能性があります。
Solution	ベンダより正式な対策が公開されています。ベンダ情報を参照して適切な対策を実施してください。
Publication Date	Dec. 10, 2015, midnight
Registration Date	Jan. 5, 2016, 1:57 p.m.
Last Update	Jan. 5, 2016, 1:57 p.m.

CVSS2.0 : 警告
Score	4.3
Vector	AV:N/AC:M/Au:N/C:N/I:P/A:N

Affected System

Samba Project

Samba 3.x

Samba 4.1.22 未満の 4.x

Samba 4.2.7 未満の 4.2.x

Samba 4.3.3 未満の 4.3.x

CVE (情報セキュリティ共通脆弱性識別子)

No	Name	URL
Common Vulnerabilities and Exposures (CVE)
1	CVE-2015-5296	http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-5296
National Vulnerability Database (NVD)
2	CVE-2015-5296	http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2015-5296
Samba
3	CVE-2015-5296: libcli/smb: make sure we require signing when we demand encryption on a session	https://git.samba.org/?p=samba.git;a=commit;h=a819d2b440aafa3138d95ff6e8b824da885a70e9
4	CVE-2015-5296: s3:libsmb: force signing when requiring encryption in do_connect()	https://git.samba.org/?p=samba.git;a=commit;h=d724f835acb9f4886c0001af32cd325dbbf1f895
5	CVE-2015-5296: s3:libsmb: force signing when requiring encryption in SMBC_server_internal()	https://git.samba.org/?p=samba.git;a=commit;h=1ba49b8f389eda3414b14410c7fbcb4041ca06b1
Samba Security Announcement
6	CVE-2015-5296.html	https://www.samba.org/samba/security/CVE-2015-5296.html

CWE (共通脆弱性タイプ一覧)

No	Name	URL
JVNDB
1	CWE-20	https://jvndb.jvn.jp/ja/cwe/CWE-20.html

ベンダー情報

No	Name	URL
Red Hat Bugzilla
1	Bug 1290292	https://bugzilla.redhat.com/show_bug.cgi?id=1290292

Change Log

No	Changed Details	Date of change
0	[2016年01月05日] 掲載	Feb. 17, 2018, 10:37 a.m.

NVD Vulnerability Information

CVE-2015-5296

Summary	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.
Publication Date	Dec. 30, 2015, 7:59 a.m.
Registration Date	Jan. 26, 2021, 2:52 p.m.
Last Update	Nov. 21, 2024, 11:32 a.m.

Affected software configurations

Configuration1	or higher	or less	more than	less than
cpe:2.3:a:samba:samba::::::::	4.3.0			4.3.3
cpe:2.3:a:samba:samba::::::::	4.2.0			4.2.7
cpe:2.3:a:samba:samba::::::::	3.2.0			4.1.22

Configuration2	or higher	or less	more than	less than
cpe:2.3:o:debian:debian_linux:8.0:::::::*
cpe:2.3:o:debian:debian_linux:7.0:::::::*

Configuration3	or higher	or less	more than	less than
cpe:2.3:o:canonical:ubuntu_linux:15.10:::::::*
cpe:2.3:o:canonical:ubuntu_linux:15.04:::::::*
cpe:2.3:o:canonical:ubuntu_linux:14.04::::esm:::
cpe:2.3:o:canonical:ubuntu_linux:12.04::::-:::

Related information, measures and tools

No	URL	タグ
1	http://lists.fedoraproject.org/pipermail/package-announce/2015-December/174076.html	Mailing List Third Party Advisory
2	http://lists.fedoraproject.org/pipermail/package-announce/2015-December/174076.html	Mailing List Third Party Advisory
3	http://lists.fedoraproject.org/pipermail/package-announce/2015-December/174391.html	Mailing List Third Party Advisory
4	http://lists.fedoraproject.org/pipermail/package-announce/2015-December/174391.html	Mailing List Third Party Advisory
5	http://lists.opensuse.org/opensuse-security-announce/2015-12/msg00019.html	Mailing List Third Party Advisory
6	http://lists.opensuse.org/opensuse-security-announce/2015-12/msg00019.html	Mailing List Third Party Advisory
7	http://lists.opensuse.org/opensuse-security-announce/2015-12/msg00020.html	Mailing List Third Party Advisory
8	http://lists.opensuse.org/opensuse-security-announce/2015-12/msg00020.html	Mailing List Third Party Advisory
9	http://lists.opensuse.org/opensuse-security-announce/2015-12/msg00032.html	Mailing List Third Party Advisory
10	http://lists.opensuse.org/opensuse-security-announce/2015-12/msg00032.html	Mailing List Third Party Advisory
11	http://lists.opensuse.org/opensuse-security-announce/2015-12/msg00033.html	Mailing List Third Party Advisory
12	http://lists.opensuse.org/opensuse-security-announce/2015-12/msg00033.html	Mailing List Third Party Advisory
13	http://lists.opensuse.org/opensuse-security-announce/2016-01/msg00002.html	Mailing List Third Party Advisory
14	http://lists.opensuse.org/opensuse-security-announce/2016-01/msg00002.html	Mailing List Third Party Advisory
15	http://lists.opensuse.org/opensuse-security-announce/2016-01/msg00017.html	Mailing List Third Party Advisory
16	http://lists.opensuse.org/opensuse-security-announce/2016-01/msg00017.html	Mailing List Third Party Advisory
17	http://lists.opensuse.org/opensuse-security-announce/2016-04/msg00042.html	Mailing List Third Party Advisory
18	http://lists.opensuse.org/opensuse-security-announce/2016-04/msg00042.html	Mailing List Third Party Advisory
19	http://lists.opensuse.org/opensuse-security-announce/2016-04/msg00047.html	Mailing List Third Party Advisory
20	http://lists.opensuse.org/opensuse-security-announce/2016-04/msg00047.html	Mailing List Third Party Advisory
21	http://lists.opensuse.org/opensuse-security-announce/2016-04/msg00048.html	Mailing List Third Party Advisory
22	http://lists.opensuse.org/opensuse-security-announce/2016-04/msg00048.html	Mailing List Third Party Advisory
23	http://www.debian.org/security/2016/dsa-3433	Third Party Advisory
24	http://www.debian.org/security/2016/dsa-3433	Third Party Advisory
25	http://www.oracle.com/technetwork/topics/security/bulletinjan2016-2867206.html	Third Party Advisory
26	http://www.oracle.com/technetwork/topics/security/bulletinjan2016-2867206.html	Third Party Advisory
27	http://www.oracle.com/technetwork/topics/security/linuxbulletinjan2016-2867209.html	Third Party Advisory
28	http://www.oracle.com/technetwork/topics/security/linuxbulletinjan2016-2867209.html	Third Party Advisory
29	http://www.securityfocus.com/bid/79732	Third Party Advisory VDB Entry
30	http://www.securityfocus.com/bid/79732	Third Party Advisory VDB Entry
31	http://www.securitytracker.com/id/1034493	Third Party Advisory VDB Entry
32	http://www.securitytracker.com/id/1034493	Third Party Advisory VDB Entry
33	http://www.ubuntu.com/usn/USN-2855-1	Third Party Advisory
34	http://www.ubuntu.com/usn/USN-2855-1	Third Party Advisory
35	http://www.ubuntu.com/usn/USN-2855-2	Third Party Advisory
36	http://www.ubuntu.com/usn/USN-2855-2	Third Party Advisory
37	https://bugzilla.redhat.com/show_bug.cgi?id=1290292	Issue Tracking Third Party Advisory
38	https://bugzilla.redhat.com/show_bug.cgi?id=1290292	Issue Tracking Third Party Advisory
39	https://git.samba.org/?p=samba.git%3Ba=commit%3Bh=1ba49b8f389eda3414b14410c7fbcb4041ca06b1
40	https://git.samba.org/?p=samba.git%3Ba=commit%3Bh=1ba49b8f389eda3414b14410c7fbcb4041ca06b1
41	https://git.samba.org/?p=samba.git%3Ba=commit%3Bh=a819d2b440aafa3138d95ff6e8b824da885a70e9
42	https://git.samba.org/?p=samba.git%3Ba=commit%3Bh=a819d2b440aafa3138d95ff6e8b824da885a70e9
43	https://git.samba.org/?p=samba.git%3Ba=commit%3Bh=d724f835acb9f4886c0001af32cd325dbbf1f895
44	https://git.samba.org/?p=samba.git%3Ba=commit%3Bh=d724f835acb9f4886c0001af32cd325dbbf1f895
45	https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05115993	Third Party Advisory
46	https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05115993	Third Party Advisory
47	https://security.gentoo.org/glsa/201612-47	Third Party Advisory
48	https://security.gentoo.org/glsa/201612-47	Third Party Advisory
49	https://www.samba.org/samba/security/CVE-2015-5296.html	Vendor Advisory
50	https://www.samba.org/samba/security/CVE-2015-5296.html	Vendor Advisory

Common Vulnerabilities List

No	CWE	Name	URL
1	CWE-20	不適切な入力確認	https://cwe.mitre.org/data/definitions/20.html