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Fencer Vulns
high 7.8

CVE-2023-1872 json

Use-after-free in Linux kernel's io_uring subsystem

published 2023-04-12 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-24074

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 23%
public exploits
0
none known

Summary

A use-after-free vulnerability in the Linux Kernel io_uring system can be exploited to achieve local privilege escalation.

The io_file_get_fixed function lacks the presence of ctx->uring_lock which can lead to a Use-After-Free vulnerability due a race condition with fixed files getting unregistered.

We recommend upgrading past commit da24142b1ef9fd5d36b76e36bab328a5b27523e8.

Patch / fix

  • linux linux_kernel 5.17
  • linux Debian 14, Debian 13, Debian 12 5.17.3-1

debian advisories DEBIAN-CVE-2023-1872

  • linux Ubuntu 22.04 LTS 5.15.0-71.78
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1035.39
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1034.42
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1032.37
  • linux-ibm Ubuntu 22.04 LTS 5.15.0-1029.32
  • linux-kvm Ubuntu 22.04 LTS 5.15.0-1032.37
  • linux-azure Ubuntu 22.04 LTS 5.15.0-1037.44
  • linux-gkeop Ubuntu 22.04 LTS 5.15.0-1019.24

ubuntu advisories UBUNTU-CVE-2023-1872

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

  • dtb-aarch64 openSUSE Leap 15.4 5.3.18-150300.59.121.1
  • kernel-64kb SLES 15 SP3-LTSS, SLE High Performance Computing 15 SP3-LTSS, SLE High Performance Computing 15 SP3-ESPOS +1 more 5.3.18-150300.59.121.2
  • kernel-syms SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE Real Time 15 SP3 +3 more 5.3.18-150300.59.121.1
  • kernel-source SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE Real Time 15 SP3 +5 more 5.3.18-150300.59.121.2
  • kernel-default SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE Real Time 15 SP3 +9 more 5.3.18-150300.59.121.2
  • kernel-preempt SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE Real Time 15 SP3 +5 more 5.3.18-150300.59.121.2
  • kernel-zfcpdump SLES 15 SP3-LTSS, Manager Server 4.2 5.3.18-150300.59.121.2
  • kernel-obs-build SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE Real Time 15 SP3 +3 more 5.3.18-150300.59.121.2

suse advisories SUSE-SU-2023:2448-1SUSE-SU-2023:2423-1SUSE-SU-2023:2401-1SUSE-SU-2023:2416-1SUSE-SU-2023:2405-1SUSE-SU-2023:2148-1

  • kernel CBL-Mariner 2.0 5.15.111.1-1

azure linux advisories AZL-26167

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-2023-1872 updated cvss 7.8

kernel: io_uring: use-after-free vulnerability in io_file_get_fixed

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    not affected: vulnerable code not present

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

Exploit prediction

0.31% chance of exploitation in the next 30 days, higher than 23% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 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 7.0 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux Kernel

Classification

Weakness
Technology feeds

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.