ntpd in ntp 4.2.x before 4.2.8p7 and 4.3.x before 4.3.92 allows authenticated users that know the private symmetric key to create arbitrarily-many ephemeral associations in order to win the clock selection of ntpd and modify a victim's clock via a Sybil attack. This issue exists because of an incomplete fix for CVE-2016-1549.
総合評価: CVE-2018-7170 は中リスク（44.8/100）。CVSS 深刻度は中。悪用される可能性が高い（EPSS 0.54%、68 パーセンタイル） 推奨対応: 影響資産を整理し、修補計画に組み込んでください。
リスクは変動します。再評価に基づき、本ページの表示内容を更新しています。
EPSS は日次で悪用されやすさの相対度合いを推定します。パーセンタイルは採点済み CVE の中での相対位置（高いほど相対的に深刻）を示します。
| # | 日付 | 旧 EPSS スコア | 新 EPSS スコア | Δ（新 − 旧） |
|---|---|---|---|---|
| 1 | 2026-05-27 | 0.64% | 0.54% | -0.10% |
| 2 | 2026-05-24 | 0.54% | 0.64% | +0.10% |
| 3 | 2026-05-19 | — | 0.54% | — |
EPSS の全履歴 （全 27 件）
この CVE の CVSS 指標。
| ベーススコア | バージョン | 深刻度 | ベクトル | 悪用しやすさ | 影響 | スコアの出典 |
|---|---|---|---|---|---|---|
| 5.3 | 3.1 | MEDIUM |
|
1.6 | 3.6 | [email protected] |
| 3.5 | 2.0 | LOW |
|
6.8 | 2.9 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
unimportant | CVE-2018-7170 unimportant priority: Debian including 2 source packages (ntp, ntpsec), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6. | https://security-tracker.debian.org/tracker/CVE-2018-7170 |
gentoo
|
normal | CVE-2018-7170: 1 GLSA(s) (201805-12), 1 atom(s) (net-misc/ntp); latest impact normal. | https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2018-7170 |
redhat
|
low | — | https://access.redhat.com/security/cve/CVE-2018-7170 |
suse
|
low | CVE-2018-7170 severity low: SUSE including 18 source package names (ntp-4.2.8p12-4.3.2, ntp-4.2.8p12-46.29.2, …), 99 product×package rows across 71 product lines (Image SLES12-SP5-Azure-BYOS, Image SLES12-SP5-Azure-Basic-On-Demand, … (71 product lines)): Fixed 99. | https://www.suse.com/security/cve/CVE-2018-7170/ |
ubuntu
|
low | CVE-2018-7170 low priority: Ubuntu including 1 source packages (ntp), 20 status rows across 20 suites (artful, bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): released 9, DNE 7, needed 3, ignored 1. | https://ubuntu.com/security/CVE-2018-7170 |
| ベンダー | 製品 | バージョン | 生の CPE |
|---|---|---|---|
| ntp | ntp | >= 4.2.0, < 4.2.8 | cpe:2.3:a:ntp:ntp:*:*:*:*:*:*:*:* |
| ntp | ntp | >= 4.3.0, < 4.3.92 | cpe:2.3:a:ntp:ntp:*:*:*:*:*:*:*:* |
| ntp | ntp | 4.2.8 | cpe:2.3:a:ntp:ntp:4.2.8:-:*:*:*:*:*:* |
| ntp | ntp | 4.2.8 | cpe:2.3:a:ntp:ntp:4.2.8:p1:*:*:*:*:*:* |
| ntp | ntp | 4.2.8 | cpe:2.3:a:ntp:ntp:4.2.8:p1-beta1:*:*:*:*:*:* |
| ntp | ntp | 4.2.8 | cpe:2.3:a:ntp:ntp:4.2.8:p1-beta2:*:*:*:*:*:* |
| ntp | ntp | 4.2.8 | cpe:2.3:a:ntp:ntp:4.2.8:p1-beta3:*:*:*:*:*:* |
| ntp | ntp | 4.2.8 | cpe:2.3:a:ntp:ntp:4.2.8:p1-beta4:*:*:*:*:*:* |
| ntp | ntp | 4.2.8 | cpe:2.3:a:ntp:ntp:4.2.8:p1-beta5:*:*:*:*:*:* |
| ntp | ntp | 4.2.8 | cpe:2.3:a:ntp:ntp:4.2.8:p1-rc1:*:*:*:*:*:* |
| ntp | ntp | 4.2.8 | cpe:2.3:a:ntp:ntp:4.2.8:p1-rc2:*:*:*:*:*:* |
| ntp | ntp | 4.2.8 | cpe:2.3:a:ntp:ntp:4.2.8:p2:*:*:*:*:*:* |
| ntp | ntp | 4.2.8 | cpe:2.3:a:ntp:ntp:4.2.8:p2-rc1:*:*:*:*:*:* |
| ntp | ntp | 4.2.8 | cpe:2.3:a:ntp:ntp:4.2.8:p2-rc2:*:*:*:*:*:* |
| ntp | ntp | 4.2.8 | cpe:2.3:a:ntp:ntp:4.2.8:p2-rc3:*:*:*:*:*:* |
| ntp | ntp | 4.2.8 | cpe:2.3:a:ntp:ntp:4.2.8:p3:*:*:*:*:*:* |
| ntp | ntp | 4.2.8 | cpe:2.3:a:ntp:ntp:4.2.8:p3-rc1:*:*:*:*:*:* |
| ntp | ntp | 4.2.8 | cpe:2.3:a:ntp:ntp:4.2.8:p3-rc2:*:*:*:*:*:* |
| ntp | ntp | 4.2.8 | cpe:2.3:a:ntp:ntp:4.2.8:p3-rc3:*:*:*:*:*:* |
| ntp | ntp | 4.2.8 | cpe:2.3:a:ntp:ntp:4.2.8:p4:*:*:*:*:*:* |
| ntp | ntp | 4.2.8 | cpe:2.3:a:ntp:ntp:4.2.8:p5:*:*:*:*:*:* |
| ntp | ntp | 4.2.8 | cpe:2.3:a:ntp:ntp:4.2.8:p6:*:*:*:*:*:* |
| synology | router_manager | >= 1.1, < 1.1.6-6931-3 | cpe:2.3:a:synology:router_manager:*:*:*:*:*:*:*:* |
| synology | skynas | < 6.1.5-15254 | cpe:2.3:a:synology:skynas:*:*:*:*:*:*:*:* |
| synology | virtual_diskstation_manager | < 6.1.6-15266 | cpe:2.3:a:synology:virtual_diskstation_manager:*:*:*:*:*:*:*:* |
| synology | diskstation_manager | >= 5.2, < 6.1.6-15266 | cpe:2.3:o:synology:diskstation_manager:*:*:*:*:*:*:*:* |
| synology | vs960hd_firmware | < 2.2.3-1505 | cpe:2.3:o:synology:vs960hd_firmware:*:*:*:*:*:*:*:* |
| netapp | hci | — | cpe:2.3:a:netapp:hci:-:*:*:*:*:*:*:* |
| netapp | solidfire | — | cpe:2.3:a:netapp:solidfire:-:*:*:*:*:*:*:* |
| hpe | hpux-ntp | < c.4.2.8.4.0 | cpe:2.3:a:hpe:hpux-ntp:*:*:*:*:*:*:*:* |
| URL | タグ |
|---|---|
| http://packetstormsecurity.com/files/146631/Slackware-Security-Advisory-ntp-Updates.html | Third Party Advisory VDB Entry |
| http://support.ntp.org/bin/view/Main/NtpBug3415 | Third Party Advisory |
| http://www.securityfocus.com/archive/1/541824/100/0/threaded | Third Party Advisory VDB Entry |
| http://www.securityfocus.com/bid/103194 | Third Party Advisory VDB Entry |
| https://bugzilla.redhat.com/show_bug.cgi?id=1550214 | Issue Tracking Third Party Advisory |
| https://security.FreeBSD.org/advisories/FreeBSD-SA-18:02.ntp.asc | Third Party Advisory |
| https://security.gentoo.org/glsa/201805-12 | Third Party Advisory |
| https://security.netapp.com/advisory/ntap-20180626-0001/ | Third Party Advisory |
| https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03962en_us | Third Party Advisory |
| https://www.synology.com/support/security/Synology_SA_18_13 | Third Party Advisory |