#VU27395 Authentication Bypass by Spoofing in ntp - CVE-2020-11868

Vulnerability identifier: #VU27395

Vulnerability risk: Low

CVSSv4.0: 1.7 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2020-11868

CWE-ID: CWE-290

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 bypass authentication and perform a denial of service (DoS) attack.

The vulnerability exists due to ntpd allows an off-path attacker to block unauthenticated synchronization via a server mode packet with a spoofed source IP address, because transmissions are rescheduled even when a packet lacks a valid origin timestamp.A remote attacker can bypass authentication and block synchronization.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

ntp: 4.2.0 - 4.3.99

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External links
https://support.ntp.org/bin/view/Main/NtpBug3592
https://bugzilla.redhat.com/show_bug.cgi?id=1716665

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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.