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Fencer Vulns
high 7.8

CVE-2023-1393 json

A flaw was found in X.Org Server Overlay Window.

published 2023-03-30 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-23649

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 32%
public exploits
0
none known

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.

Patch / fix

  • x.org x_server 21.1.8
  • xwayland Debian 14, Debian 13, Debian 12 2:22.1.9-1
  • xorg-server Debian 14, Debian 13, Debian 12 2:21.1.7-2

debian advisories DEBIAN-CVE-2023-1393

  • tigervnc Ubuntu 20.04 LTS 1.10.1+dfsg-3ubuntu0.20.04.1
  • tigervnc Ubuntu 22.04 LTS 1.12.0+dfsg-4ubuntu0.22.04.1
  • xwayland Ubuntu 22.04 LTS 2:22.1.1-1ubuntu0.6
  • xorg-server Ubuntu 18.04 LTS 2:1.19.6-1ubuntu4.15
  • xorg-server Ubuntu 20.04 LTS 2:1.20.13-1ubuntu1~20.04.8
  • xorg-server Ubuntu 22.04 LTS 2:21.1.3-2ubuntu2.9
  • xorg-server-hwe-18.04 Ubuntu 18.04 LTS 2:1.20.8-2ubuntu2.2~18.04.11

ubuntu advisories UBUNTU-CVE-2023-1393

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • xorg-x11-server RHEL 9 1.20.11-19.el9
  • xorg-x11-server-Xdmx RHEL 9 1.20.11-19.el9
  • xorg-x11-server-Xorg RHEL 9 1.20.11-19.el9
  • xorg-x11-server-Xvfb RHEL 9 1.20.11-19.el9
  • xorg-x11-server-Xnest RHEL 9 1.20.11-19.el9
  • xorg-x11-server-common RHEL 9 1.20.11-19.el9
  • xorg-x11-server-source RHEL 9 1.20.11-19.el9
  • xorg-x11-server-Xephyr RHEL 9 1.20.11-19.el9

red hat advisories RHSA-2025:12751RHSA-2023:6340RHSA-2023:6341RHSA-2023:1549RHSA-2023:1548RHSA-2023:1551

  • xwayland SLE Workstation Extension 15 SP4, openSUSE Leap 15.4 21.1.4-150400.3.15.1
  • xorg-x11-server SLES 12 SP2-BCL 7.6_1.18.3-76.66.1
  • xorg-x11-server SLES for SAP 15 SP3, SLES for SAP 15 SP2, SLES 15 SP3-LTSS +11 more 1.20.3-150200.22.5.72.1
  • xorg-x11-server SLES for SAP 12 SP5, SLES 12 SP5, SLE Software Development Kit 12 SP5 1.19.6-10.49.1
  • xorg-x11-server SLE Module for Development Tools 15 SP4, SLE Module for Basesystem 15 SP4, openSUSE Leap 15.4 1.20.3-150400.38.22.1
  • xorg-x11-server SLES for SAP 12 SP4, SLES 12 SP4-LTSS, SLES 12 SP4-ESPOS +2 more 1.19.6-4.48.1
  • xorg-x11-server SLES for SAP 15 SP1, SLES 15 SP1-LTSS, SLE High Performance Computing 15 SP1-LTSS 1.20.3-150100.14.5.42.1

suse advisories SUSE-SU-2023:1716-1SUSE-SU-2023:1680-1SUSE-SU-2023:1679-1SUSE-SU-2023:1678-1SUSE-SU-2023:1677-1SUSE-SU-2023:1675-1

  • xorg-x11-server openSUSE Tumbleweed 21.1.7-2.1
  • xwayland openSUSE Tumbleweed 23.1.1-1.1

opensuse advisories openSUSE-SU-2024:12827-1openSUSE-SU-2024:12834-1

  • xorg-x11-server-Xdmx AlmaLinux 8 1.20.11-17.el8
  • xorg-x11-server-Xorg AlmaLinux 8 1.20.11-17.el8
  • xorg-x11-server-Xvfb AlmaLinux 8 1.20.11-17.el8
  • xorg-x11-server-Xnest AlmaLinux 8 1.20.11-17.el8
  • xorg-x11-server-common AlmaLinux 8 1.20.11-17.el8
  • xorg-x11-server-source AlmaLinux 8 1.20.11-17.el8
  • xorg-x11-server-Xephyr AlmaLinux 8 1.20.11-17.el8
  • xorg-x11-server-Xwayland AlmaLinux 8 21.1.3-12.el8

almalinux advisories ALSA-2023:6916ALSA-2023:6917ALSA-2023:6340ALSA-2023:6341ALSA-2023:1551ALSA-2023:1592

  • tigervnc Rocky Linux 9 1.12.0-5.el9_1.2

rocky linux advisories RLSA-2023:1592

  • xorg-x11-server CBL-Mariner 2.0, Azure Linux 3.0 1.20.10-4
  • xorg-x11-server Azure Linux 3.0 1.20.10-6

azure linux advisories AZL-25859AZL-35358AZL-44478

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-1393 updated cvss 7.8

xorg-x11-server: X.Org Server Overlay Window Use-After-Free Local Privilege Escalation Vulnerability

  • Red Hat Enterprise Linux 6 xorg-x11-server, xorg-x11-server-Xdmx, xorg-x11-server-Xorg, xorg-x11-server-Xvfb, xorg-x11-server-Xnest, xorg-x11-server-common, +2 more
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat CodeReady Linux Builder (v. 8) xorg-x11-server-source 1.20.11-17.el8
    fixed: vendor fix RHSA-2023:6916
  • Red Hat CodeReady Linux Builder (v. 9) xorg-x11-server-source 1.20.11-19.el9
    fixed: vendor fix RHSA-2023:6340
  • Red Hat Enterprise Linux AppStream (v. 8) tigervnc 1.12.0-9.el8_7.3, xorg-x11-server 1.20.11-17.el8, tigervnc-icons 1.12.0-9.el8_7.3, tigervnc-server 1.12.0-9.el8_7.3, tigervnc-license 1.12.0-9.el8_7.3, tigervnc-selinux 1.12.0-9.el8_7.3, +9 more
    fixed: vendor fix RHSA-2023:1551
  • Red Hat Enterprise Linux AppStream (v. 9) tigervnc 1.12.0-5.el9_1.2, xorg-x11-server 1.20.11-19.el9, tigervnc-icons 1.12.0-5.el9_1.2, tigervnc-server 1.12.0-5.el9_1.2, tigervnc-license 1.12.0-5.el9_1.2, tigervnc-selinux 1.12.0-5.el9_1.2, +9 more
    fixed: vendor fix RHSA-2023:1592
  • Red Hat Enterprise Linux AppStream AUS (v. 8.2) tigervnc 1.9.0-15.el8_2.3, tigervnc-icons 1.9.0-15.el8_2.3, tigervnc-server 1.9.0-15.el8_2.3, tigervnc-license 1.9.0-15.el8_2.3, tigervnc-server-applet 1.9.0-15.el8_2.3, tigervnc-server-module 1.9.0-15.el8_2.3, +1 more
    fixed: vendor fix RHSA-2023:1549
  • Red Hat Enterprise Linux AppStream E4S (v. 8.1) tigervnc 1.9.0-16.el8_1.3, tigervnc-icons 1.9.0-16.el8_1.3, tigervnc-server 1.9.0-16.el8_1.3, tigervnc-license 1.9.0-16.el8_1.3, tigervnc-server-applet 1.9.0-16.el8_1.3, tigervnc-server-module 1.9.0-16.el8_1.3, +1 more
    fixed: vendor fix RHSA-2023:1600
  • Red Hat Enterprise Linux AppStream E4S (v. 8.2) tigervnc 1.9.0-15.el8_2.3, tigervnc-icons 1.9.0-15.el8_2.3, tigervnc-server 1.9.0-15.el8_2.3, tigervnc-license 1.9.0-15.el8_2.3, tigervnc-server-applet 1.9.0-15.el8_2.3, tigervnc-server-module 1.9.0-15.el8_2.3, +1 more
    fixed: vendor fix RHSA-2023:1549
show 9 more
  • Red Hat Enterprise Linux AppStream EUS (v.8.4) tigervnc 1.11.0-8.el8_4.2, tigervnc-icons 1.11.0-8.el8_4.2, tigervnc-server 1.11.0-8.el8_4.2, tigervnc-license 1.11.0-8.el8_4.2, tigervnc-selinux 1.11.0-8.el8_4.2, tigervnc-server-module 1.11.0-8.el8_4.2, +1 more
    fixed: vendor fix RHSA-2023:1548
  • Red Hat Enterprise Linux AppStream EUS (v.8.6) tigervnc 1.12.0-6.el8_6.3, tigervnc-icons 1.12.0-6.el8_6.3, tigervnc-server 1.12.0-6.el8_6.3, tigervnc-license 1.12.0-6.el8_6.3, tigervnc-selinux 1.12.0-6.el8_6.3, tigervnc-server-module 1.12.0-6.el8_6.3, +1 more
    fixed: vendor fix RHSA-2023:1598
  • Red Hat Enterprise Linux AppStream EUS (v.9.0) tigervnc 1.11.0-22.el9_0.2, tigervnc-icons 1.11.0-22.el9_0.2, tigervnc-server 1.11.0-22.el9_0.2, tigervnc-license 1.11.0-22.el9_0.2, tigervnc-selinux 1.11.0-22.el9_0.2, tigervnc-server-module 1.11.0-22.el9_0.2, +1 more
    fixed: vendor fix RHSA-2023:1599
  • Red Hat Enterprise Linux AppStream TUS (v. 8.2) tigervnc 1.9.0-15.el8_2.3, tigervnc-icons 1.9.0-15.el8_2.3, tigervnc-server 1.9.0-15.el8_2.3, tigervnc-license 1.9.0-15.el8_2.3, tigervnc-server-applet 1.9.0-15.el8_2.3, tigervnc-server-module 1.9.0-15.el8_2.3, +1 more
    fixed: vendor fix RHSA-2023:1549
  • Red Hat Enterprise Linux Client (v. 7) tigervnc 1.8.0-25.el7_9, tigervnc-icons 1.8.0-25.el7_9, tigervnc-server 1.8.0-25.el7_9, tigervnc-license 1.8.0-25.el7_9, xorg-x11-server 1.20.4-23.el7_9, xorg-x11-server-Xorg 1.20.4-23.el7_9, +3 more Red Hat Enterprise Linux Client Optional (v. 7) xorg-x11-server-Xdmx 1.20.4-23.el7_9, xorg-x11-server-Xvfb 1.20.4-23.el7_9, tigervnc-server-applet 1.8.0-25.el7_9, tigervnc-server-module 1.8.0-25.el7_9, xorg-x11-server-Xnest 1.20.4-23.el7_9, xorg-x11-server-source 1.20.4-23.el7_9, +1 more Red Hat Enterprise Linux ComputeNode Optional (v. 7) tigervnc 1.8.0-25.el7_9, tigervnc-icons 1.8.0-25.el7_9, tigervnc-server 1.8.0-25.el7_9, xorg-x11-server 1.20.4-23.el7_9, xorg-x11-server-Xdmx 1.20.4-23.el7_9, xorg-x11-server-Xorg 1.20.4-23.el7_9, +8 more
    fixed: vendor fix RHSA-2023:1594
  • Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION) tigervnc 1.1.0-25.el6_10.13, tigervnc-server 1.1.0-25.el6_10.13
    fixed: vendor fix RHSA-2025:12751
  • Red Hat Enterprise Linux Server (v. 7) tigervnc 1.8.0-25.el7_9, tigervnc-icons 1.8.0-25.el7_9, tigervnc-server 1.8.0-25.el7_9, tigervnc-license 1.8.0-25.el7_9, xorg-x11-server 1.20.4-23.el7_9, xorg-x11-server-Xorg 1.20.4-23.el7_9, +3 more
    fixed: vendor fix RHSA-2023:1594
  • Red Hat Enterprise Linux Server Optional -EXTENSION (v. 6 ELS -EXTENSION) tigervnc-server-applet 1.1.0-25.el6_10.13, tigervnc-server-module 1.1.0-25.el6_10.13
    fixed: vendor fix RHSA-2025:12751
  • Red Hat Enterprise Linux Server Optional (v. 7) xorg-x11-server-Xdmx 1.20.4-23.el7_9, xorg-x11-server-Xvfb 1.20.4-23.el7_9, tigervnc-server-applet 1.8.0-25.el7_9, tigervnc-server-module 1.8.0-25.el7_9, xorg-x11-server-Xnest 1.20.4-23.el7_9, xorg-x11-server-source 1.20.4-23.el7_9, +1 more Red Hat Enterprise Linux Workstation (v. 7) tigervnc 1.8.0-25.el7_9, tigervnc-icons 1.8.0-25.el7_9, tigervnc-server 1.8.0-25.el7_9, tigervnc-license 1.8.0-25.el7_9, xorg-x11-server 1.20.4-23.el7_9, xorg-x11-server-Xorg 1.20.4-23.el7_9, +3 more Red Hat Enterprise Linux Workstation Optional (v. 7) xorg-x11-server-Xdmx 1.20.4-23.el7_9, xorg-x11-server-Xvfb 1.20.4-23.el7_9, tigervnc-server-applet 1.8.0-25.el7_9, tigervnc-server-module 1.8.0-25.el7_9, xorg-x11-server-Xnest 1.20.4-23.el7_9, xorg-x11-server-source 1.20.4-23.el7_9, +1 more
    fixed: vendor fix RHSA-2023:1594

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

cisa ICSA-24-046-11 updated cvss 7.8

Siemens SCALANCE XCM-/XRM-300

  • Siemens SCALANCE XCH328 (6GK5328-4TS01-2EC2) <V2.4 Siemens SCALANCE XCM324 (6GK5324-8TS01-2AC2) <V2.4 Siemens SCALANCE XCM328 (6GK5328-4TS01-2AC2) <V2.4 Siemens SCALANCE XCM332 (6GK5332-0GA01-2AC2) <V2.4 Siemens SCALANCE XRH334 (24 V DC, 8xFO, CC) (6GK5334-2TS01-2ER3) <V2.4 Siemens SCALANCE XRM334 (2x230 V AC, 8xFO) (6GK5334-2TS01-4AR3) <V2.4
    +5 more products
    Siemens SCALANCE XRM334 (2x230 V AC, 12xFO) (6GK5334-3TS01-4AR3) <V2.4 Siemens SCALANCE XRM334 (24 V DC, 8xFO) (6GK5334-2TS01-2AR3) <V2.4 Siemens SCALANCE XRM334 (24 V DC, 12xFO) (6GK5334-3TS01-2AR3) <V2.4 Siemens SCALANCE XRM334 (230 V AC, 8xFO) (6GK5334-2TS01-3AR3) <V2.4 Siemens SCALANCE XRM334 (230 V AC, 12xFO) (6GK5334-3TS01-3AR3) <V2.4
    affected: fixed in V2.4 support.industry.siemens.com

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
9 mo ago

Exploit prediction

0.38% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • n/a xorg-server

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.