#VU29542 Input validation error in ntp - CVE-2018-8956

Vulnerability identifier: #VU29542

Vulnerability risk: Low

CVSSv4.0: 1.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2018-8956

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 attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient validation of user-supplied input when processing NTP packets. A remote attacker that controls a slave server or is part of the same broadcast can prevent a broadcast client from synchronizing its clock with a broadcast NTP server via spoofed mode 3 and mode 5 packets.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

ntp: 4.2.8p10 - 4.2.8p13

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External links
https://www.ntp.org/
https://arxiv.org/abs/2005.01783
https://nikhiltripathi.in/NTP_attack.pdf
https://security.netapp.com/advisory/ntap-20200518-0006/
https://tools.ietf.org/html/rfc5905

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

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