Denial of service in ntpd

1) NULL pointer dereference

EUVDB-ID: #VU20339

Risk: Low

CVSSv4.0: 4.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2019-8936

CWE-ID: CWE-476 - NULL Pointer Dereference

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error when processing authenticated mode 6 packets. A remote attacker can send malicious authenticated mode 6 (ntpq) packet from a permitted network address, trigger a NULL pointer dereference error and crash ntpd.

Mitigation

Install update from vendor's website.

Vulnerable software versions

ntp: 4.0.72 - 4.3.93

CPE2.3

• cpe:2.3:a:ntp_org:ntp:4.0.72:*:*:*:*:*:*:*
• cpe:2.3:a:ntp_org:ntp:4.0.73:*:*:*:*:*:*:*
• cpe:2.3:a:ntp_org:ntp:4.0.90:*:*:*:*:*:*:*

External links

https://support.ntp.org/bin/view/Main/NtpBug3565
https://bugs.ntp.org/show_bug.cgi?id=3565
https://lists.opensuse.org/opensuse-security-announce/2019-04/msg00032.html
https://lists.opensuse.org/opensuse-security-announce/2019-04/msg00036.html
https://packetstormsecurity.com/files/152915/FreeBSD-Security-Advisory-FreeBSD-SA-19-04.ntp.html
https://support.ntp.org/bin/view/Main/SecurityNotice
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2NVS2CSG2TQ663CXOZZUJN4STQPMENNP/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/JBGXY7OKWOLT6X6JAPVZRFEP4FLCGGST/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/KQDNHNYOJK2SRSGO23GQ2RXTOUY2HLNN/
https://seclists.org/bugtraq/2019/May/39
https://security.FreeBSD.org/advisories/FreeBSD-SA-19:04.ntp.asc
https://security.gentoo.org/glsa/201903-15
https://security.netapp.com/advisory/ntap-20190503-0001/
https://support.f5.com/csp/article/K61363039

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.