CVE-2016-7426
CVE-2016-7426 is a high-severity vulnerability in Ntp with a CVSS 3.x base score of 7.5. Its EPSS exploit-prediction score of 12% places it in the 96th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-400.
Key facts
- Severity: High (CVSS 3.x base score 7.5)
- CVSS v2: 4.3
- EPSS exploit prediction: 12% (96th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-400
- Affected product: Ntp
- Published:
- Last modified:
Description
NTP before 4.2.8p9 rate limits responses received from the configured sources when rate limiting for all associations is enabled, which allows remote attackers to cause a denial of service (prevent responses from the sources) by sending responses with a spoofed source address.
Frequently asked questions
- What is CVE-2016-7426?
- NTP before 4.2.8p9 rate limits responses received from the configured sources when rate limiting for all associations is enabled, which allows remote attackers to cause a denial of service (prevent responses from the sources) by sending responses with a spoofed source address.
- How severe is CVE-2016-7426?
- CVE-2016-7426 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
- Is CVE-2016-7426 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 12% (96th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2016-7426?
- CVE-2016-7426 primarily affects Ntp. In total, 91 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2016-7426?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2016-7426 published?
- CVE-2016-7426 was published on 2017-01-13 and last updated on 2026-06-17.
References
- http://nwtime.org/ntp428p9_release/
- http://rhn.redhat.com/errata/RHSA-2017-0252.html
- http://support.ntp.org/bin/view/Main/NtpBug3071
- http://support.ntp.org/bin/view/Main/SecurityNotice#Recent_Vulnerabilities
- http://www.securityfocus.com/bid/94451
- http://www.securitytracker.com/id/1037354
- https://bto.bluecoat.com/security-advisory/sa139
- https://h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03706en_us
- https://security.FreeBSD.org/advisories/FreeBSD-SA-16:39.ntp.asc
- https://usn.ubuntu.com/3707-2/
- https://www.kb.cert.org/vuls/id/633847
Affected products (91)
- cpe:2.3:a:ntp:ntp:*:*:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p203:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p204:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p205:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p206:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p207:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p208:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p209:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p210:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p211:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p212:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p213:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p214:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p215:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p216:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p217:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p218:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p219:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p220:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p221:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p222:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p223:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p224:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p225:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p226:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p227:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p228:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p229:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p230:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p231_rc1:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p232_rc1:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p233_rc1:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p234_rc1:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p235_rc1:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p236_rc1:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p237_rc1:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p238_rc1:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p239_rc1:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p240_rc1:*:*:*:*:*:*
- cpe:2.3:a:ntp:ntp:4.2.5:p241_rc1:*:*:*:*:*:*
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Browse all CWE-400 (Uncontrolled Resource Consumption) vulnerabilities →
Threat intelligence
Threat-intel indicators referencing this CVE:
- 197.248.207.139 (ipv4-addr)
- 135.129.128.247 (ipv4-addr)
- 119.201.59.224 (ipv4-addr)
- 125.212.244.35 (ipv4-addr)
- 202.29.220.126 (ipv4-addr)
- 93.42.227.251 (ipv4-addr)
- 82.209.191.11 (ipv4-addr)
- 119.204.60.250 (ipv4-addr)