How severe is CVE-2019-6443?

CVE-2019-6443 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.

Is CVE-2019-6443 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 67% (99th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2019-6443?

CVE-2019-6443 affects Ntpsec. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2019-6443?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2019-6443 published?

CVE-2019-6443 was published on 2019-01-16 and last updated on 2026-06-17.

CVE-2019-6443

CVE-2019-6443 is a critical-severity vulnerability in Ntpsec with a CVSS 3.x base score of 9.1. Its EPSS exploit-prediction score of 67% places it in the 99th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-125.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
CVSS v2: 6.4
EPSS exploit prediction: 67% (99th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-125
Affected product: Ntpsec
Published: 2019-01-16
Last modified: 2026-06-17

Description

An issue was discovered in NTPsec before 1.1.3. Because of a bug in ctl_getitem, there is a stack-based buffer over-read in read_sysvars in ntp_control.c in ntpd.

Frequently asked questions

What is CVE-2019-6443?: An issue was discovered in NTPsec before 1.1.3. Because of a bug in ctl_getitem, there is a stack-based buffer over-read in read_sysvars in ntp_control.c in ntpd.
How severe is CVE-2019-6443?: CVE-2019-6443 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.
Is CVE-2019-6443 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 67% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-6443?: CVE-2019-6443 affects Ntpsec. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2019-6443?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2019-6443 published?: CVE-2019-6443 was published on 2019-01-16 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:ntpsec:ntpsec:*:*:*:*:*:*:*:*

More vulnerabilities in Ntpsec

CVE-2019-6444 — Critical (CVSS 9.1): An issue was discovered in NTPsec before 1.1.3. process_control() in ntp_control.c has a stack-based buffer over-read…
CVE-2023-4012 — High (CVSS 7.5): ntpd will crash if the server is not NTS-enabled (no certificate) and it receives an NTS-enabled client request (mode…
CVE-2019-6445 — Medium (CVSS 6.5): An issue was discovered in NTPsec before 1.1.3. An authenticated attacker can cause a NULL pointer dereference and ntpd…
CVE-2019-6442 — Medium (CVSS 6.5): An issue was discovered in NTPsec before 1.1.3. An authenticated attacker can write one byte out of bounds in ntpd via…
CVE-2021-22212 — Medium (CVSS 4.0): ntpkeygen can generate keys that ntpd fails to parse. NTPsec 1.2.0 allows ntpkeygen to generate keys with '#'…
CVE-2016-1551 — Low (CVSS 3.7): ntpd in NTP 4.2.8p3 and NTPsec a5fb34b9cc89b92a8fef2f459004865c93bb7f92 relies on the underlying operating system to…

All CVEs affecting Ntpsec →

Other CWE-125 (Out-of-bounds Read) vulnerabilities

CVE-2026-24826 — Critical (CVSS 10.0): Out-of-bounds Write, Divide By Zero, NULL Pointer Dereference, Use of Uninitialized Resource, Out-of-bounds Read,…
CVE-2024-22004 — Critical (CVSS 10.0): Due to length check, an attacker with privilege access on a Linux Nonsecure operating system can trigger a…
CVE-2021-41556 — Critical (CVSS 10.0): sqclass.cpp in Squirrel through 2.2.5 and 3.x through 3.1 allows an out-of-bounds read (in the core interpreter) that…
CVE-2021-21777 — Critical (CVSS 10.0): An information disclosure vulnerability exists in the Ethernet/IP UDP handler functionality of EIP Stack Group OpENer…
CVE-2017-14451 — Critical (CVSS 10.0): An exploitable out-of-bounds read vulnerability exists in libevm (Ethereum Virtual Machine) of CPP-Ethereum. A…
CVE-2013-0767 — Critical (CVSS 10.0): The nsSVGPathElement::GetPathLengthScale function in Mozilla Firefox before 18.0, Firefox ESR 10.x before 10.0.12 and…

Browse all CWE-125 (Out-of-bounds Read) vulnerabilities →