CVE-2016-7434

Exp

The read_mru_list function in NTP before 4.2.8p9 allows remote attackers to cause a denial of service (crash) via a crafted mrulist query.

Published: 2017-01-13 Last update: 2026-05-13 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2016-7434 is rated High Exploit Risk (82.8/100): CVSS High severity, with high exploitation likelihood (EPSS 62.38%, 98th percentile). 2 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +3.37% over the last day, indicating growing attacker interest. Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2016-7434

EDB-ID Source Kind Published Link
40806 exploit_db edb 2016-11-21 Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2016-7434

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-04 59.01% 62.38% +3.37%
2 2026-03-01 62.38% 59.01% -3.37%
3 2026-02-04 — 62.38% —

Full EPSS history (47 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-7434

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2016-7434

OS Trackers for CVE-2016-7434

vendor priority summary link
debian not yet assigned CVE-2016-7434 not yet assigned priority: Debian including 1 source packages (ntp), 1 status rows across 1 suites (bullseye): resolved 1. https://security-tracker.debian.org/tracker/CVE-2016-7434
redhat low — https://access.redhat.com/security/cve/CVE-2016-7434
suse medium CVE-2016-7434 severity moderate: SUSE including 22 source package names (ntp-4.2.8p10-63.3, ntp-4.2.8p11-2.12, …), 82 product×package rows across 55 product lines (Image SLES12-SP5-Azure-BYOS, Image SLES12-SP5-Azure-Basic-On-Demand, … (55 product lines)): Fixed 82. https://www.suse.com/security/cve/CVE-2016-7434/
ubuntu low CVE-2016-7434 low priority: Ubuntu including 1 source packages (ntp), 6 status rows across 6 suites (precise, trusty, upstream, xenial, yakkety, zesty): not-affected 3, released 3. https://ubuntu.com/security/CVE-2016-7434

Affected software / configurations for CVE-2016-7434

Vendor Product Version Raw CPE
ntp ntp >= 4.3.0, < 4.3.94 cpe:2.3:a:ntp:ntp:*:*:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p100:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p101:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p102:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p103:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p104:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p105:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p106:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p107:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p108:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p109:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p110:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p111:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p112:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p113:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p114:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p115:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p116:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p117:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p118:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p119:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p120:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p121:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p122:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p123:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p124:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p125:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p126:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p127:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p128:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p129:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p130:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p131:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p132:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p133:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p134:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p135:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p136:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p137:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p138:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p139:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p140:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p141:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p142:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p143:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p144:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p145:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p146:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p147:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p148:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p149:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p150:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p151:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p152:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p153:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p154:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p155:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p156:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p157:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p158:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p159:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p160:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p161:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p162:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p163:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p164:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p165:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p166:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p170:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p171:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p172:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p173:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p174:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p175:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p176:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p177:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p178:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p179:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p180:*:*:*:*:*:*
ntp ntp 4.2.7 cpe:2.3:a:ntp:ntp:4.2.7:p181:*:*:*:*:*:*

References for CVE-2016-7434

URL Tags
http://nwtime.org/ntp428p9_release/ Third Party Advisory
http://support.ntp.org/bin/view/Main/NtpBug3082 Issue Tracking Mitigation Vendor Advisory
http://support.ntp.org/bin/view/Main/SecurityNotice#Recent_Vulnerabilities Release Notes Vendor Advisory
http://www.securityfocus.com/bid/94448 Third Party Advisory VDB Entry
http://www.securitytracker.com/id/1037354 Third Party Advisory VDB Entry
https://bto.bluecoat.com/security-advisory/sa139 Third Party Advisory
https://h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03706en_us Third Party Advisory
https://security.FreeBSD.org/advisories/FreeBSD-SA-16:39.ntp.asc Third Party Advisory
https://www.exploit-db.com/exploits/40806/ Exploit Third Party Advisory VDB Entry
https://www.kb.cert.org/vuls/id/633847 Third Party Advisory US Government Resource
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