NVD Vulnerability Detail

CVE-2016-8858

Summary	The kex_input_kexinit function in kex.c in OpenSSH 6.x and 7.x through 7.3 allows remote attackers to cause a denial of service (memory consumption) by sending many duplicate KEXINIT requests. NOTE: a third party reports that "OpenSSH upstream does not consider this as a security issue."
Publication Date	Dec. 9, 2016, 8:59 p.m.
Registration Date	Jan. 26, 2021, 2:19 p.m.
Last Update	Nov. 21, 2024, noon

CVSS3.0 : HIGH
スコア	7.5
Vector	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
攻撃元区分(AV)	ネットワーク
攻撃条件の複雑さ(AC)	低
攻撃に必要な特権レベル(PR)	不要
利用者の関与(UI)	不要
影響の想定範囲(S)	変更なし
機密性への影響(C)	なし
完全性への影響(I)	なし
可用性への影響(A)	高

CVSS2.0 : HIGH
Score	7.8
Vector	AV:N/AC:L/Au:N/C:N/I:N/A:C
攻撃元区分(AV)	ネットワーク
攻撃条件の複雑さ(AC)	低
攻撃前の認証要否(Au)	不要
機密性への影響(C)	なし
完全性への影響(I)	なし
可用性への影響(A)	高
Get all privileges.	いいえ
Get user privileges	いいえ
Get other privileges	いいえ
User operation required	いいえ

Affected software configurations

Configuration1	or higher	or less	more than	less than
cpe:2.3:a:openbsd:openssh:6.9:::::::*
cpe:2.3:a:openbsd:openssh:7.3:::::::*
cpe:2.3:a:openbsd:openssh:7.1:::::::*
cpe:2.3:a:openbsd:openssh:7.2:::::::*
cpe:2.3:a:openbsd:openssh:6.8:::::::*
cpe:2.3:a:openbsd:openssh:7.0:::::::*

Related information, measures and tools

No	URL	タグ
1	http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/kex.c.diff?r1=1.126&r2=1.127&f=h	Issue Tracking Vendor Advisory
2	http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/kex.c.diff?r1=1.126&r2=1.127&f=h	Issue Tracking Vendor Advisory
3	http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/kex.c?rev=1.127&content-type=text/x-cvsweb-markup	Issue Tracking Vendor Advisory
4	http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/kex.c?rev=1.127&content-type=text/x-cvsweb-markup	Issue Tracking Vendor Advisory
5	http://www.openwall.com/lists/oss-security/2016/10/19/3	Mailing List Third Party Advisory
6	http://www.openwall.com/lists/oss-security/2016/10/19/3	Mailing List Third Party Advisory
7	http://www.openwall.com/lists/oss-security/2016/10/20/1	Mailing List Third Party Advisory
8	http://www.openwall.com/lists/oss-security/2016/10/20/1	Mailing List Third Party Advisory
9	http://www.securityfocus.com/bid/93776	Third Party Advisory VDB Entry
10	http://www.securityfocus.com/bid/93776	Third Party Advisory VDB Entry
11	http://www.securitytracker.com/id/1037057	Third Party Advisory VDB Entry
12	http://www.securitytracker.com/id/1037057	Third Party Advisory VDB Entry
13	https://bugzilla.redhat.com/show_bug.cgi?id=1384860	Issue Tracking
14	https://bugzilla.redhat.com/show_bug.cgi?id=1384860	Issue Tracking
15	https://cert-portal.siemens.com/productcert/pdf/ssa-412672.pdf
16	https://cert-portal.siemens.com/productcert/pdf/ssa-412672.pdf
17	https://ftp.openbsd.org/pub/OpenBSD/patches/6.0/common/013_ssh_kexinit.patch.sig	Patch Vendor Advisory
18	https://ftp.openbsd.org/pub/OpenBSD/patches/6.0/common/013_ssh_kexinit.patch.sig	Patch Vendor Advisory
19	https://github.com/openssh/openssh-portable/commit/ec165c392ca54317dbe3064a8c200de6531e89ad	Issue Tracking Patch Third Party Advisory
20	https://github.com/openssh/openssh-portable/commit/ec165c392ca54317dbe3064a8c200de6531e89ad	Issue Tracking Patch Third Party Advisory
21	https://security.FreeBSD.org/advisories/FreeBSD-SA-16:33.openssh.asc	Third Party Advisory
22	https://security.FreeBSD.org/advisories/FreeBSD-SA-16:33.openssh.asc	Third Party Advisory
23	https://security.gentoo.org/glsa/201612-18	Third Party Advisory
24	https://security.gentoo.org/glsa/201612-18	Third Party Advisory
25	https://security.netapp.com/advisory/ntap-20180201-0001/	Third Party Advisory
26	https://security.netapp.com/advisory/ntap-20180201-0001/	Third Party Advisory

Common Vulnerabilities List

No	CWE	Name	URL
1	CWE-399	リソース管理の問題	https://cwe.mitre.org/data/definitions/399.html

JVN Vulnerability Information

OpenSSH の kex.c の kex_input_kexinit 関数におけるサービス運用妨害 (DoS) の脆弱性

Title	OpenSSH の kex.c の kex_input_kexinit 関数におけるサービス運用妨害 (DoS) の脆弱性
Summary	未確定本件は、脆弱性として確定していません。 OpenSSH の kex.c の kex_input_kexinit 関数には、サービス運用妨害 (メモリ消費) 状態にされる脆弱性が存在します。なお、サードパーティは「OpenSSH のアップストリームは本件をセキュリティ問題として考慮していない」と報告しています。
Possible impacts	リモートの攻撃者により、多数の重複した KEXINIT リクエストを送信されることで、サービス運用妨害 (メモリ消費) 状態にされる可能性があります。
Solution	ベンダ情報および参考情報を参照して適切な対策を実施してください。
Publication Date	Oct. 10, 2016, midnight
Registration Date	Dec. 12, 2016, 5:21 p.m.
Last Update	Dec. 12, 2016, 5:21 p.m.

Affected System

OpenBSD

OpenSSH 6.x

OpenSSH 7.3 までの 7.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-2016-8858	http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-8858
National Vulnerability Database (NVD)
2	CVE-2016-8858	http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-8858

CWE (共通脆弱性タイプ一覧)

No	Name	URL
JVNDB
1	CWE-399	https://jvndb.jvn.jp/ja/cwe/CWE-399.html

ベンダー情報

No	Name	URL
GitHub
1	upstream commit (openssh/openssh-portable@ec165c3)	https://github.com/openssh/openssh-portable/commit/ec165c392ca54317dbe3064a8c200de6531e89ad
OpenBSD
2	Diff for /src/usr.bin/ssh/kex.c between version 1.126 and 1.127	http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/kex.c.diff?r1=1.126&r2=1.127&f=h
3	src/usr.bin/ssh/kex.c - view - 1.127	http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/kex.c?rev=1.127&content-type=text/x-cvsweb-markup
Red Hat Bugzilla
4	Bug 1384860	https://bugzilla.redhat.com/show_bug.cgi?id=1384860

その他

No	Name	URL
関連文書
1	OpenSSH: Memory exhaustion issue found in OpenSSH	http://www.openwall.com/lists/oss-security/2016/10/19/3

Change Log

No	Changed Details	Date of change
0	[2016年12月12日] 掲載	Feb. 17, 2018, 10:37 a.m.

Configuration1	or higher	or less	more than	less than
cpe:2.3:a:openbsd:openssh:6.9:::::::*
cpe:2.3:a:openbsd:openssh:7.3:::::::*
cpe:2.3:a:openbsd:openssh:7.1:::::::*
cpe:2.3:a:openbsd:openssh:7.2:::::::*
cpe:2.3:a:openbsd:openssh:6.8:::::::*
cpe:2.3:a:openbsd:openssh:7.0:::::::*