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Full vulnerability report · 2023
CVE-2023-26554High confidence

An adversary may be able to attack a client ntpq process, but cannot attack ntpd

n/a · n/a

5.6MediumCVSS 3.1
Recommended action
Within 7 days

Medium technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Patch available
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
SSA-238730 · CSAF 2.0 · revision 1 · interimSiemens ProductCERTSSA-238730: Out-of-Bounds Write Vulnerabilities in SITOP UPS1600 before V2.5.4
4 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • SITOP UPS1600 10 A Ethernet/ PROFINET (6EP4134-3AB00-2AY0)
  • SITOP UPS1600 20 A Ethernet/ PROFINET (6EP4136-3AB00-2AY0)
  • SITOP UPS1600 40 A Ethernet/ PROFINET (6EP4137-3AB00-2AY0)
  • SITOP UPS1600 EX 20 A Ethernet PROFINET (6EP4136-3AC00-2AY0)
Summary
mstolfp in libntp/mstolfp.c in NTP 4.2.8p15 has an out-of-bounds write when adding a '\0' character. An adversary may be able to attack a client ntpq process, but cannot attack ntpd.
Remediation
Update to V2.5.4 or later version
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2023-30351

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

Medium technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

mstolfp in libntp/mstolfp.c in NTP 4.2.8p15 has an out-of-bounds write when adding a '\0' character. An adversary may be able to attack a client ntpq process, but cannot attack ntpd.

What

mstolfp in libntp/mstolfp.c in NTP 4.2.8p15 has an out-of-bounds write when adding a '\0' character. An adversary may be able to attack a client ntpq process, but cannot attack ntpd.

Why

A bounds error lets data be written beyond the intended memory region, potentially corrupting control data.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

mstolfp in libntp/mstolfp.c in NTP 4.2.8p15 has an out-of-bounds write when adding a '\0' character. An adversary may be able to attack a client ntpq process, but cannot attack ntpd.

Why

A bounds error lets data be written beyond the intended memory region, potentially corrupting control data.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Reference recorded

CISA Vulnrichment records proof-of-concept exploitation in its SSVC data. BlackTree has not independently executed or validated exploit material.

Likely attack path
a network path → Out-of-bounds Write → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
High: exploitation depends on specific conditions
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-787 ↗

CWE-787: Out-of-bounds Write. The product writes data past the end, or before the beginning, of the intended buffer.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CLowConfidentiality impact: A successful attack can cause a limited loss.ILowIntegrity impact: A successful attack can cause a limited loss.ALowAvailability impact: A successful attack can cause a limited loss.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedCWE-787Public exploit reference
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-W-2023-0938ntp: Mehrere Schwachstellen

Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in ntp ausnutzen, um nicht näher definierte Auswirkungen zu erreichen. Die Ausnutzung erfordert eine bestimmte Konfiguration und ggf. das Mitwirken eines Administrators, beispielsweise durch Social Engineering.

Official advisory
CERT-FR · French · CERTFR-2026-AVI-0326Multiples vulnérabilités dans les produits VMware

cord?id=CVE-2023-1386 Référence CVE CVE-2023-2007 https://www.cve.org/CVERecord?id=CVE-2023-2007 Référence CVE CVE-2023-23931 https://www.cve.org/CVERecord?id=CVE-2023-23931 Référence CVE CVE-2023-25951 https://www.cve.org/CVERecord?id=CVE-2023-25951 Référence CVE CVE-2023-26112 https://www.cve.org/CVERecord?id=CVE-2023-26112 Référence CVE CVE-2023-26242 https://www.cve.org/CVERecord?id=CVE-2023-26242 Référence CVE CVE-2023-26551 https://www.cve.org/CVERecord?id=CVE-2023-26551 Référence CVE CVE-2023-26552 https://www.cve.org/CVERecord?id=CVE-2023-26552 Référence CVE CVE-2023-26553 https://www.cve.org/CVERecord?id=CVE-2023-26553 Référence CVE CVE-2023-26554 https://www.cve.org/CVERecord?id=CVE-2023-26554 Référence CVE CVE-2023-26555 https://www.cve.org/CVERecord?id=CVE-2023-26555 Référence CVE CVE-2023-26586 https://www.cve.org/CVERecord?id=CVE-2023-26586 Référence CVE CVE-2023-2828 https://www.cve.org/CVERecord?id=CVE-2023-2828 Référence CVE CVE-2023-28374 https://www.cve.org/CVERecord?id=CVE-2023-28374 Référence CVE CVE-2023-28720 https://www.cve.org/CVERecord?id=CVE-2023-28720 Référence CVE CVE-2023-29383 https://www.cve.org/CVERecord?id=CVE-2023-29383 Référence CVE CVE-2023-2975 https://www.cve.org/CVERecord?id=CVE-2023-2975 Référence CVE CVE-2023-29935 https://www.cve.org/CVERecord?id=CVE-

Official advisory
CERT-FR · French · CERTFR-2026-AVI-0316Multiples vulnérabilités dans les produits VMware

cord?id=CVE-2023-1386 Référence CVE CVE-2023-2007 https://www.cve.org/CVERecord?id=CVE-2023-2007 Référence CVE CVE-2023-23931 https://www.cve.org/CVERecord?id=CVE-2023-23931 Référence CVE CVE-2023-25951 https://www.cve.org/CVERecord?id=CVE-2023-25951 Référence CVE CVE-2023-26112 https://www.cve.org/CVERecord?id=CVE-2023-26112 Référence CVE CVE-2023-26242 https://www.cve.org/CVERecord?id=CVE-2023-26242 Référence CVE CVE-2023-26551 https://www.cve.org/CVERecord?id=CVE-2023-26551 Référence CVE CVE-2023-26552 https://www.cve.org/CVERecord?id=CVE-2023-26552 Référence CVE CVE-2023-26553 https://www.cve.org/CVERecord?id=CVE-2023-26553 Référence CVE CVE-2023-26554 https://www.cve.org/CVERecord?id=CVE-2023-26554 Référence CVE CVE-2023-26555 https://www.cve.org/CVERecord?id=CVE-2023-26555 Référence CVE CVE-2023-26586 https://www.cve.org/CVERecord?id=CVE-2023-26586 Référence CVE CVE-2023-2828 https://www.cve.org/CVERecord?id=CVE-2023-2828 Référence CVE CVE-2023-28374 https://www.cve.org/CVERecord?id=CVE-2023-28374 Référence CVE CVE-2023-28720 https://www.cve.org/CVERecord?id=CVE-2023-28720 Référence CVE CVE-2023-29383 https://www.cve.org/CVERecord?id=CVE-2023-29383 Référence CVE CVE-2023-2975 https://www.cve.org/CVERecord?id=CVE-2023-2975 Référence CVE CVE-2023-29935 https://www.cve.org/CVERecord?id=CVE-

Official advisory
CERT-FR · French · CERTFR-2024-AVI-0478Multiples vulnérabilités dans les produits Siemens

cord?id=CVE-2023-2124 Référence CVE CVE-2023-21255 https://www.cve.org/CVERecord?id=CVE-2023-21255 Référence CVE CVE-2023-21808 https://www.cve.org/CVERecord?id=CVE-2023-21808 Référence CVE CVE-2023-2269 https://www.cve.org/CVERecord?id=CVE-2023-2269 Référence CVE CVE-2023-24895 https://www.cve.org/CVERecord?id=CVE-2023-24895 Référence CVE CVE-2023-24897 https://www.cve.org/CVERecord?id=CVE-2023-24897 Référence CVE CVE-2023-24936 https://www.cve.org/CVERecord?id=CVE-2023-24936 Référence CVE CVE-2023-26552 https://www.cve.org/CVERecord?id=CVE-2023-26552 Référence CVE CVE-2023-26553 https://www.cve.org/CVERecord?id=CVE-2023-26553 Référence CVE CVE-2023-26554 https://www.cve.org/CVERecord?id=CVE-2023-26554 Référence CVE CVE-2023-27321 https://www.cve.org/CVERecord?id=CVE-2023-27321 Référence CVE CVE-2023-28260 https://www.cve.org/CVERecord?id=CVE-2023-28260 Référence CVE CVE-2023-28319 https://www.cve.org/CVERecord?id=CVE-2023-28319 Référence CVE CVE-2023-28484 https://www.cve.org/CVERecord?id=CVE-2023-28484 Référence CVE CVE-2023-29331 https://www.cve.org/CVERecord?id=CVE-2023-29331 Référence CVE CVE-2023-29469 https://www.cve.org/CVERecord?id=CVE-2023-29469 Référence CVE CVE-2023-32032 https://www.cve.org/CVERecord?id=CVE-2023-32032 Référence CVE CVE-2023-33126 https://www.cve.org/CVERecord?id=

Official advisory
CERT-FR · French · CERTFR-2023-AVI-0836Multiples vulnérabilités dans les produits Juniper

-Bulletin-Junos-OS-PTX-Series-and-QFX10000-Series-Received-flow-routes-which-aren-t-installed-as-the-hardware-doesn-t-support-them-lead-to-an-FPC-heap-memory-leak-CVE-2023-22392 Référence CVE CVE-2022-2097 https://www.cve.org/CVERecord?id=CVE-2022-2097 Référence CVE CVE-2022-2274 https://www.cve.org/CVERecord?id=CVE-2022-2274 Référence CVE CVE-2023-22392 https://www.cve.org/CVERecord?id=CVE-2023-22392 Référence CVE CVE-2023-26551 https://www.cve.org/CVERecord?id=CVE-2023-26551 Référence CVE CVE-2023-26552 https://www.cve.org/CVERecord?id=CVE-2023-26552 Référence CVE CVE-2023-26553 https://www.cve.org/CVERecord?id=CVE-2023-26553 Référence CVE CVE-2023-26554 https://www.cve.org/CVERecord?id=CVE-2023-26554 Référence CVE CVE-2023-26555 https://www.cve.org/CVERecord?id=CVE-2023-26555 Référence CVE CVE-2023-36839 https://www.cve.org/CVERecord?id=CVE-2023-36839 Référence CVE CVE-2023-36841 https://www.cve.org/CVERecord?id=CVE-2023-36841 Référence CVE CVE-2023-36843 https://www.cve.org/CVERecord?id=CVE-2023-36843 Référence CVE CVE-2023-44175 https://www.cve.org/CVERecord?id=CVE-2023-44175 Référence CVE CVE-2023-44176 https://www.cve.org/CVERecord?id=CVE-2023-44176 Référence CVE CVE-2023-44177 https://www.cve.org/CVERecord?id=CVE-2023-44177 Référence CVE CVE-2023-44178 https://www.cve.org/CVERecord?id=

Official advisory
NCSC-NL · Dutch · NCSC-2024-0246Kwetsbaarheden verholpen in Siemens producten

De kwetsbaarheden stellen een kwaadwillende mogelijk in staat aanvallen uit te voeren die kunnen leiden tot de volgende categorieën schade: - Denial-of-Service (DoS) - Manipulatie van gegevens - Omzeilen van beveiligingsmaatregel - (Remote) code execution (Administrator/Root rechten) - (Remote) code execution (Gebruikersrechten) - Toegang tot systeemgegevens - Verhoogde gebruikersrechten De kwaadwillende heeft hiervoor toegang nodig tot de productieomgeving. Het is goed gebruik een dergelijke omgeving niet publiek toegankelijk te hebben.

Official advisory
NCSC-NL · Dutch · NCSC-2024-0411Kwetsbaarheden verholpen in Oracle Database producten

Een kwaadwillende kan de kwetsbaarheden misbruiken om aanvallen uit te voeren die kunnen leiden tot de volgende categorieën schade: - Denial-of-Service (DoS) - Manipuleren van data - Toegang tot gevoelige gegevens

Official advisory
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
SITOP UPS1600 10 A Ethernet/ PROFINET (6EP4134-3AB00-2AY0); SITOP UPS1600 20 A Ethernet/ PROFINET (6EP4136-3AB00-2AY0); SITOP UPS1600 40 A Ethernet/ PROFINET (6EP4137-3AB00-2AY0); SITOP UPS1600 EX 20 A Ethernet PROFINET (6EP4136-3AC00-2AY0)
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
Update to V2.5.4 or later version
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 11 Apr 2023 · Last source change 11 Feb 2025, 15:26 UTC · CWE-787 · Out-of-bounds Write

CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2023-30351
Product sourceVendor CSAF · Siemens ProductCERT
Remediation sourceVendor CSAF · Siemens ProductCERT
CWE sourceCISA ADP
NVD statusNVD modified after enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates →

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
ENISA EUVD · EUVD-2023-30351↗Vendor CSAF · Siemens ProductCERT↗CISA Vulnrichment SSVC evidence↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2023-26554 · cve.blacktree.nl