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Fencer Vulns
medium 5.5

CVE-2023-42365 json

A use-after-free vulnerability was discovered in BusyBox v.1.36.1 via a crafted awk pattern in the awk.c copyvar function.

published 2023-11-27 2 y ago modified 2026-06-17 4 mo ago also EUVD-2023-46818

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 33%
public exploits
0
none known

Summary

A use-after-free vulnerability was discovered in BusyBox v.1.36.1 via a crafted awk pattern in the awk.c copyvar function.

Patch / fix

  • busybox Debian 12 1:1.35.0-4+deb12u1
  • busybox Debian 14, Debian 13 1:1.37.0-1

debian advisories DEBIAN-CVE-2023-42365

  • busybox Ubuntu 24.04 LTS 1:1.36.1-6ubuntu3.1

ubuntu advisories UBUNTU-CVE-2023-42365

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

  • busybox SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +1 more 1.35.0-150400.3.14.1
  • busybox-links openSUSE Leap 15.6 1.37.0-150500.7.7.2
  • busybox SLE Module for Basesystem 15 SP6, SLE High Performance Computing 15 SP5-ESPOS, openSUSE Leap 15.6 +3 more 1.37.0-150500.10.11.1
  • busybox SLE Module for Basesystem 15 SP7 1.37.0-150700.18.4.1
  • busybox SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 1.35.0-10.3.1

suse advisories SUSE-SU-2026:0892-1SUSE-SU-2026:0872-1SUSE-SU-2025:03271-1SUSE-SU-2025:03271-2SUSE-SU-2025:03205-1

  • busybox openSUSE Tumbleweed 1.37.0-5.1

opensuse advisories openSUSE-SU-2025:15361-1

  • busybox Alpine 3.17 1.35.0-r31
  • busybox Alpine 3.18 1.36.1-r7
  • busybox Alpine 3.19 1.36.1-r19
  • busybox Alpine 3.20 1.36.1-r29
  • busybox Alpine 3.24, Alpine 3.23, Alpine 3.22 +1 more 1.36.1-r30

alpine advisories ALPINE-CVE-2023-42365

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • busybox CBL-Mariner 2.0 1.35.0-11
  • busybox Azure Linux 3.0 1.36.1-7

azure linux advisories AZL-33494AZL-34576

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-2023-42365 updated cvss 7.8

busybox: use-after-free

  • Red Hat Enterprise Linux 6 busybox, busybox-petitboot
    affected: no fix planned “Out of support scope”

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-26-043-06 updated cvss 7.8

Siemens SINEC OS

  • Siemens RUGGEDCOM RST2428P (6GK6242-6PA00) < 3.3
    affected: fixed in V3.3 support.industry.siemens.com
  • Siemens SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family < 3.3
    affected: fixed in V3.3
  • Siemens SCALANCE XCH328 (6GK5328-4TS01-2EC2) < 3.3 Siemens SCALANCE XCM324 (6GK5324-8TS01-2AC2) < 3.3 Siemens SCALANCE XCM328 (6GK5328-4TS01-2AC2) < 3.3 Siemens SCALANCE XCM332 (6GK5332-0GA01-2AC2) < 3.3 Siemens SCALANCE XRH334 (24 V DC, 8xFO, CC) (6GK5334-2TS01-2ER3) < 3.3 Siemens SCALANCE XRM334 (2x230 V AC, 8xFO) (6GK5334-2TS01-4AR3) < 3.3
    +8 more products
    Siemens SCALANCE XRM334 (2x230 V AC, 12xFO) (6GK5334-3TS01-4AR3) < 3.3 Siemens SCALANCE XRM334 (2x230V AC, 2x10G, 24xSFP, 8xSFP+) (6GK5334-5TS01-4AR3) < 3.3 Siemens SCALANCE XRM334 (24 V DC, 8xFO) (6GK5334-2TS01-2AR3) < 3.3 Siemens SCALANCE XRM334 (24 V DC, 12xFO) (6GK5334-3TS01-2AR3) < 3.3 Siemens SCALANCE XRM334 (24V DC, 2x10G, 24xSFP, 8xSFP+) (6GK5334-5TS01-2AR3) < 3.3 Siemens SCALANCE XRM334 (230 V AC, 8xFO) (6GK5334-2TS01-3AR3) < 3.3 Siemens SCALANCE XRM334 (230 V AC, 12xFO) (6GK5334-3TS01-3AR3) < 3.3 Siemens SCALANCE XRM334 (230V AC, 2x10G, 24xSFP, 8xSFP+) (6GK5334-5TS01-3AR3) < 3.3
    affected: fixed in V3.3 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

Exploit prediction

0.39% chance of exploitation in the next 30 days, higher than 33% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • bugs.busybox.net https://bugs.busybox.net/show_bug.cgi?id=15871 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

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.