CVE-2019-6443
CriticalExploitedPublic exploitBecause of a bug in ctl_getitem, there is a stack-based buffer over-read in read_sysvars in ntp_control.c in ntpd.
Published Jan 16, 2019 · Updated Aug 4, 2026 · Also known as DEBIAN-CVE-2019-6443, UBUNTU-CVE-2019-6443
Key Facts
Patch immediately- CVE-2019-6443 is a critical-severity vulnerability (CVSS 9.1 v3.1) affecting Ntpsec, libntpc1 (suse), ntpsec-devel (suse) and 3 more products.
- It is exploited in the wild, listed in Industry KEV feed since Oct 20, 2025. Public exploit code is available.
- EPSS estimates a 67% probability of exploitation in the next 30 days.
- Fixed versions are available, including libntpc1 1.2.1-1.2, Ntpsec 1.1.0+dfsg1-1ubuntu0.2, Ntpsec 1.1.3-lp150.2.3.1.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
9.1
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
EPSS (30-day exploit likelihood)
67%
Higher than 99.2% of all scored CVEs
Exploited in the wild
Yes
1 catalog listing
Public exploit code
Available
Proof-of-concept or weaponized module
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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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| Industry KEV feed | Oct 20, 2025 | n/a | Not reported |
Required action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Affected Products
38 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| NtpsecNtpsec | See advisory | 1.1.3 |
| libntpc1suse | See advisory | 1.2.1-1.2 |
| ntpsec-develsuse | See advisory | 1.2.1-1.2 |
| ntpsec-docsuse | See advisory | 1.2.1-1.2 |
| ntpsec-utilssuse | See advisory | 1.1.3-lp150.2.3.1 |
Patched Releases
libntpc1
1.2.1-1.2
Ntpsec
1.1.0+dfsg1-1ubuntu0.2, 1.1.3-lp150.2.3.1, 1.1.3-r0, 1.1.3+dfsg1-1, 1.2.1-1.2, 1.1.3
ntpsec-devel
1.2.1-1.2
ntpsec-doc
1.2.1-1.2
ntpsec-utils
1.1.3-lp150.2.3.1, 1.2.1-1.2
python3-ntp
1.1.3-lp150.2.3.1, 1.2.1-1.2
Timeline
Publicly disclosed
Jan 16, 2019
Added to Industry KEV feed
Oct 20, 2025
Last updated
Aug 4, 2026
Weakness Type
- CWE-125 Out-of-bounds Read
References
- advisoryhttps://github.com/ntpsec/ntpsec/blob/NTPsec_1_1_3/NEWS
- advisoryhttps://security-tracker.debian.org/tracker/CVE-2019-6443
- advisoryhttps://ubuntu.com/security/CVE-2019-6443
- advisoryhttps://www.cve.org/CVERecord?id=CVE-2019-6443
- exploithttps://dumpco.re/blog/ntpsec-bugs
FAQ
Common Questions.
An issue was discovered in NTPsec before 1.1.3.
Affected: Ntpsec; libntpc1 (suse); ntpsec-devel (suse), among others. The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed since Oct 20, 2025.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including libntpc1 1.2.1-1.2, Ntpsec 1.1.0+dfsg1-1ubuntu0.2, Ntpsec 1.1.3-lp150.2.3.1.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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