#VU39824 Input validation error in ntp - CVE-2016-7431

Vulnerability identifier: #VU39824

Vulnerability risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2016-7431

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
ntp
Server applications / Other server solutions

Vendor: ntp.org

Description

The vulnerability allows a remote non-authenticated attacker to manipulate data.

NTP before 4.2.8p9 allows remote attackers to bypass the origin timestamp protection mechanism via an origin timestamp of zero. NOTE: this vulnerability exists because of a CVE-2015-8138 regression.

Mitigation
Install update from vendor's website.

Vulnerable software versions

ntp: 4.2.8

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External links
https://nwtime.org/ntp428p9_release/
https://support.ntp.org/bin/view/Main/NtpBug3102
https://support.ntp.org/bin/view/Main/SecurityNotice#Recent_Vulnerabilities
https://www.oracle.com/technetwork/security-advisory/cpuoct2017-3236626.html
https://www.securityfocus.com/bid/94454
https://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://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbhf03883en_us
https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbhf03899en_us
https://www.kb.cert.org/vuls/id/633847

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.