CVE-2023-4012 | Incomplete Internal State Distinction in ntpsec

ntpd will crash if the server is not NTS-enabled (no certificate) and it receives an NTS-enabled client request (mode 3).

Published: 2023-08-07 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-4012 is rated Moderate Risk (46/100): CVSS High severity, with low exploitation likelihood (EPSS 0.23%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-4012

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-11-21 0.26% 0.23% -0.03%
2 2025-11-18 0.23% 0.26% +0.03%
3 2025-04-15 — 0.23% —

Full EPSS history (14 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-4012

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2023-4012

OS Trackers for CVE-2023-4012

vendor priority summary link
alpine high CVE-2023-4012: 1 source package rows (ntpsec); 6 state rows across 6 repos (3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 6, open 0. https://security.alpinelinux.org/vuln/CVE-2023-4012
debian unimportant CVE-2023-4012 unimportant priority: Debian including 1 source packages (ntpsec), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2023-4012
ubuntu medium CVE-2023-4012 medium priority: Ubuntu including 1 source packages (ntpsec), 10 status rows across 10 suites (bionic, focal, jammy, lunar, mantic, noble, oracular, trusty, upstream, xenial): ignored 6, not-affected 3, released 1. https://ubuntu.com/security/CVE-2023-4012

Affected software / configurations for CVE-2023-4012

Vendor Product Version Raw CPE
ntpsec ntpsec 1.2.2 cpe:2.3:a:ntpsec:ntpsec:1.2.2:*:*:*:*:*:*:*

References for CVE-2023-4012

URL Tags
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1038422 Issue Tracking Third Party Advisory
https://gitlab.com/NTPsec/ntpsec/-/issues/794 Issue Tracking Vendor Advisory
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