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CVE-2023-42364· NVD / CVE Program· CNA mitre

A use-after-free vulnerability in BusyBox v.1.36.1 allows attackers to cause a denial of service via a crafted awk pattern in the awk.c eval

Noroxi assessment

Priority: Monitor (action score 22/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.43% (FIRST EPSS).
  • Someone with local access to the system can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
  • Fixed version: busybox (Alpine:v3.17) 1.35.0-r31; busybox (Alpine:v3.18) 1.36.1-r7; busybox (Alpine:v3.19) 1.36.1-r19.

Low priority for now. Upgrade to busybox (Alpine:v3.17) 1.35.0-r31; busybox (Alpine:v3.18) 1.36.1-r7; busybox (Alpine:v3.19) 1.36.1-r19 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

A use-after-free vulnerability in BusyBox v.1.36.1 allows attackers to cause a denial of service via a crafted awk pattern in the awk.c evaluate function.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Nov 27, 2023
Updated
Jun 17, 2026
EPSS
0.4% · 36th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CISA SSVC decision

Exploitation
proof of concept
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2023-42364

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
busyboxbusybox

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • busybox busybox1.36.1

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Alpine:v3.17busyboxbefore 1.35.0-r311.35.0-r31
Alpine:v3.18busyboxbefore 1.36.1-r71.36.1-r7
Alpine:v3.19busyboxbefore 1.36.1-r191.36.1-r19
Alpine:v3.20busyboxbefore 1.36.1-r291.36.1-r29
Alpine:v3.21busyboxbefore 1.36.1-r301.36.1-r30
Debian:11busyboxbefore 1:1.30.1-6+deb11u11:1.30.1-6+deb11u1
Debian:12busyboxbefore 1:1.35.0-4+deb12u11:1.35.0-4+deb12u1
Debian:13busyboxbefore 1:1.37.0-11:1.37.0-1
openSUSE:Leap 15.6busybox-linksbefore 1.37.0-150500.7.7.21.37.0-150500.7.7.2
openSUSE:Tumbleweedbusyboxbefore 1.37.0-5.11.37.0-5.1
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSbusyboxbefore 1.35.0-150400.3.14.11.35.0-150400.3.14.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6busyboxbefore 1.37.0-150500.10.11.11.37.0-150500.10.11.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6busyboxbefore 1.37.0-150500.10.11.11.37.0-150500.10.11.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7busyboxbefore 1.37.0-150700.18.4.11.37.0-150700.18.4.1
SUSE:Linux Enterprise Server 12 SP5-LTSSbusyboxbefore 1.35.0-10.3.11.35.0-10.3.1

Same product

busybox: all records

Other highest-scoring records for the same primary product.

  • CVE-2018-1000517BusyBox project BusyBox wget version prior to commit 8e2174e9bd836e53c8b9c6e00d1bc6e2a718686e contains a Buffer Overflow vulnerability in Bu
    49Plan
  • CVE-2016-2148Heap-based buffer overflow in the DHCP client (udhcpc) in BusyBox before 1.25.0 allows remote attackers to have unspecified impact via vecto
    47Plan
  • CVE-2022-48174There is a stack overflow vulnerability in ash.c:6030 in busybox before 1.35.
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2023-39810Aug 28, 2023 · An issue in the CPIO command of Busybox v1.33.2 allows attackers to execute a directory traversal.
    31Monitor
  • ← EarlierCVE-2023-42363Nov 27, 2023 · A use-after-free vulnerability was discovered in xasprintf function in xfuncs_printf.c:344 in BusyBox v.1.36.1.
    22Monitor
  • Later →CVE-2023-42365Nov 27, 2023 · A use-after-free vulnerability was discovered in BusyBox v.1.36.1 via a crafted awk pattern in the awk.c copyvar function.
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
alpine:busybox1.35.0-r31 · Alpine:v3.17Package registry (OSV)
debian:busybox1:1.35.0-4+deb12u1 · Debian:12Package registry (OSV)
opensuse:busybox1.37.0-150500.10.11.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:busybox-links1.37.0-150500.7.7.2 · openSUSE:Leap 15.6Package registry (OSV)
suse:busybox1.37.0-150500.10.11.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP6Package registry (OSV)
suse:busybox1.37.0-150700.18.4.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP7Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2023-423630 days apartA use-after-free vulnerability was discovered in xasprintf function in xfuncs_printf.c:344 in BusyBox v.1.36.1.
    22Monitor
  • CVE-2023-423650 days apartA use-after-free vulnerability was discovered in BusyBox v.1.36.1 via a crafted awk pattern in the awk.c copyvar function.
    22Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • No account or password is required.
  • A user must open a link or visit a page.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

nvd-primary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

c
free(dev->buf);/* ... another thread is still running ... */process(dev->buf);

Fixed

c
lock(&dev->lock);free(dev->buf);dev->buf = NULL;unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records