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Full vulnerability report · 2023
CVE-2023-1393High confidence

A flaw was found in X.Org Server Overlay Window

n/a · xorg-server

7.8HighCVSS 3.1
Recommended action
Within 7 days

High technical severity; 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-806742 · CSAF 2.0 · revision 1 · interimSiemens ProductCERTSSA-806742: Multiple Vulnerabilities in SCALANCE XCM-/XRM-300 before V2.4
11 known affected

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

  • SCALANCE XCH328 (6GK5328-4TS01-2EC2)
  • SCALANCE XCM324 (6GK5324-8TS01-2AC2)
  • SCALANCE XCM328 (6GK5328-4TS01-2AC2)
  • SCALANCE XCM332 (6GK5332-0GA01-2AC2)
  • SCALANCE XRH334 (24 V DC, 8xFO, CC) (6GK5334-2TS01-2ER3)
  • SCALANCE XRM334 (230 V AC, 12xFO) (6GK5334-3TS01-3AR3)
  • SCALANCE XRM334 (230 V AC, 8xFO) (6GK5334-2TS01-3AR3)
  • SCALANCE XRM334 (24 V DC, 12xFO) (6GK5334-3TS01-2AR3)
  • SCALANCE XRM334 (24 V DC, 8xFO) (6GK5334-2TS01-2AR3)
  • SCALANCE XRM334 (2x230 V AC, 12xFO) (6GK5334-3TS01-4AR3)
  • SCALANCE XRM334 (2x230 V AC, 8xFO) (6GK5334-2TS01-4AR3)
Summary
A flaw was found in X.Org Server Overlay Window. A Use-After-Free may lead to local privilege escalation. If a client explicitly destroys the compositor overlay window (aka COW), the Xserver would leave a dangling pointer to that window in the CompScreen structure, which will trigger a use-after-free later.
Remediation
Update to V2.4 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-2023-23649

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

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

A flaw was found in X.Org Server Overlay Window. A Use-After-Free may lead to local privilege escalation. If a client explicitly destroys the compositor overlay window (aka COW), the Xserver would leave a dangling pointer to that window in the CompScreen structure, which will trigger a use-after-free later.

What

A flaw was found in X.Org Server Overlay Window. A Use-After-Free may lead to local privilege escalation. If a client explicitly destroys the compositor overlay window (aka COW), the Xserver would leave a dangling pointer to that window in the CompScreen structure, which will trigger a use-after-free later.

Why

The program can continue using memory after it has been released, producing unsafe and attacker-influenceable behaviour.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may gain additional privileges.

What

A flaw was found in X.Org Server Overlay Window. A Use-After-Free may lead to local privilege escalation. If a client explicitly destroys the compositor overlay window (aka COW), the Xserver would leave a dangling pointer to that window in the CompScreen structure, which will trigger a use-after-free later.

Why

The program can continue using memory after it has been released, producing unsafe and attacker-influenceable behaviour.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may gain additional privileges.

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.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
local access → Use After Free → gain additional privileges
Attack surface
Local
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
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-416 ↗

CWE-416: Use After Free. The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.

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

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

AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
Privilege escalationCWE-416
A

Official authority intelligence

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

BSI · German · WID-SEC-2026-0169Oracle JD Edwards: Mehrere Schwachstellen

Ein entfernter, anonymer oder authentisierter Angreifer kann mehrere Schwachstellen in Oracle JD Edwards ausnutzen, um die Vertraulichkeit, Integrität und Verfügbarkeit zu gefährden.

Official advisory ↗
BSI · German · WID-SEC-2023-2917Xerox FreeFlow Print Server: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in Xerox FreeFlow Print Server ausnutzen, um die Vertraulichkeit, Verfügbarkeit und Integrität des Systems zu gefährden.

Official advisory ↗
BSI · German · WID-SEC-2023-0793X.Org X11: Schwachstelle ermöglicht Privilegieneskalation oder Codeausführung

Ein lokaler Angreifer kann eine Schwachstelle in X.Org X11 ausnutzen, um seine Privilegien zu erhöhen und beliebigen Code auszuführen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20230405Security Bulletin 05 Apr 2023

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 05 Apr 2023, published on 5 April 2023. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2024-AVI-0119Multiples vulnérabilités dans les produits Siemens

.cve.org/CVERecord?id=CVE-2023-0401 Référence CVE CVE-2023-0494 https://www.cve.org/CVERecord?id=CVE-2023-0494 Référence CVE CVE-2023-0567 https://www.cve.org/CVERecord?id=CVE-2023-0567 Référence CVE CVE-2023-0568 https://www.cve.org/CVERecord?id=CVE-2023-0568 Référence CVE CVE-2023-0590 https://www.cve.org/CVERecord?id=CVE-2023-0590 Référence CVE CVE-2023-0662 https://www.cve.org/CVERecord?id=CVE-2023-0662 Référence CVE CVE-2023-1206 https://www.cve.org/CVERecord?id=CVE-2023-1206 Référence CVE CVE-2023-1255 https://www.cve.org/CVERecord?id=CVE-2023-1255 Référence CVE CVE-2023-1380 https://www.cve.org/CVERecord?id=CVE-2023-1380 Référence CVE CVE-2023-1393 https://www.cve.org/CVERecord?id=CVE-2023-1393 Référence CVE CVE-2023-1611 https://www.cve.org/CVERecord?id=CVE-2023-1611 Référence CVE CVE-2023-1670 https://www.cve.org/CVERecord?id=CVE-2023-1670 Référence CVE CVE-2023-1838 https://www.cve.org/CVERecord?id=CVE-2023-1838 Référence CVE CVE-2023-1855 https://www.cve.org/CVERecord?id=CVE-2023-1855 Référence CVE CVE-2023-1859 https://www.cve.org/CVERecord?id=CVE-2023-1859 Référence CVE CVE-2023-1989 https://www.cve.org/CVERecord?id=CVE-2023-1989 Référence CVE CVE-2023-1990 https://www.cve.org/CVERecord?id=CVE-2023-1990 Référence CVE CVE-2023-2002 https://www.cve.org/CVERecord?id=CVE-2023-2002 Ré

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2023-006458X.Org Foundation の X.Org Server 他複数ベンダの製品における解放済みメモリの使用に関する脆弱性

X.Org Foundation の X.Org Server 他複数ベンダの製品には、解放済みメモリの使用に関する脆弱性が存在します。

Official advisory ↗
NCSC-NL · Dutch · NCSC-2026-0031Kwetsbaarheden verholpen in Oracle JD Edwards

Recent vulnerabilities in Oracle JD Edwards EnterpriseOne Tools and X.Org Server, including a significant flaw with a CVSS score of 7.8 and a use-after-free issue, pose risks of local privilege escalation.

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
Fixed
An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
Action
Update to V2.4 or later version
Workaround
No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04

Evidence and provenance

Published 30 Mar 2023 · Last source change 22 Jan 2026, 04:55 UTC · CWE-416 · Use After Free

CVE recordCVE.org · 5.2
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-2023-23649
Product sourceVendor CSAF · Siemens ProductCERT
Remediation sourceVendor CSAF · Siemens ProductCERT
CWE sourceCNA
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
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2023-23649↗Vendor CSAF · Siemens ProductCERT↗Patch or update reference↗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-2023-1393 · cve.blacktree.nl