What’s Vulnerable › Vulnerabilities

CVE-2015-7974

• Severity: high (CVSS 7.7 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 5.7% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2016-01-26 · updated 2026-06-17
• Weakness: CWE-287

Description

NTP 4.x before 4.2.8p6 and 4.3.x before 4.3.90 do not verify peer associations of symmetric keys when authenticating packets, which might allow remote attackers to conduct impersonation attacks via an arbitrary trusted key, aka a "skeleton key."

Affected products

• Debian Linux: 8.0, 9.0
• Clustered Data ONTAP: all versions
• NetApp Oncommand Balance: all versions
• NTP: from 4.2.0 before 4.2.8; from 4.3.0 before 4.3.90; 4.2.8, 4.2.8-p1, 4.2.8-p1-beta1, 4.2.8-p1-beta2, 4.2.8-p1-beta3, 4.2.8-p1-beta4 (+13) — fixed in 4.2.8, 4.3.90
• Siemens Tim 4R-Ie Dnp3 Firmware: all versions
• Siemens Tim 4R-Ie Firmware: all versions

How to fix

Upgrade to a fixed version: NTP 4.2.8, 4.3.90. Check the vendor advisory for mitigations.

References

• http://bugs.ntp.org/show_bug.cgi?id=2936
• http://rhn.redhat.com/errata/RHSA-2016-2583.html
• http://support.ntp.org/bin/view/Main/NtpBug2936
• http://www.debian.org/security/2016/dsa-3629
• http://www.securityfocus.com/bid/81960
• http://www.securitytracker.com/id/1034782
• http://www.talosintel.com/reports/TALOS-2016-0071/
• https://cert-portal.siemens.com/productcert/pdf/ssa-497656.pdf
• https://h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbhf03750en_us
• https://h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbhf03766en_us
• https://security.FreeBSD.org/advisories/FreeBSD-SA-16:09.ntp.asc
• https://security.gentoo.org/glsa/201607-15

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