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CVE-2023-6546· NVD / CVE Program· CNA redhat

Kernel: gsm multiplexing race condition leads to privilege escalation

Noroxi assessment

Priority: Monitor (action score 28/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.73% (FIRST EPSS); higher than 53.5% of all records.
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: bpftool (AlmaLinux:8) 4.18.0-513.24.1.el8_9; kernel (AlmaLinux:8) 4.18.0-513.24.1.el8_9; kernel-abi-stablelists (AlmaLinux:8) 4.18.0-513.24.1.el8_9.

Low priority for now. Upgrade to bpftool (AlmaLinux:8) 4.18.0-513.24.1.el8_9; kernel (AlmaLinux:8) 4.18.0-513.24.1.el8_9; kernel-abi-stablelists (AlmaLinux:8) 4.18.0-513.24.1.el8_9 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 race condition was found in the GSM 0710 tty multiplexor in the Linux kernel. This issue occurs when two threads execute the GSMIOC_SETCONF ioctl on the same tty file descriptor with the gsm line discipline enabled, and can lead to a use-after-free problem on a struct gsm_dlci while restarting the gsm mux. This could allow a local unprivileged user to escalate their privileges on the system.

HighCVSS 7.0 · v3.1—Proof of concept Fix available
Published
Dec 21, 2023
Updated
Aug 6, 2026
EPSS
0.7% · 53th percentile

Report tools

JSON

Action score

28

Monitor

Low priority for now.

CVSS
28 / 40 · 7.0 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.7%

CNA vs NVD score

NVD
7.0
CNA · redhat
7.0
agree

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • Proof of concept exists, no weaponized module
  • A fix has been released

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

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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
linuxlinux kernel
fedoraprojectfedora
redhatenterprise linux

Affected versions

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

  • fedoraproject fedora39
  • linux linux kernelbefore 6.5
  • linux linux kernel6.5
  • redhat enterprise linux8.0
  • redhat enterprise linux9.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.

  • Red Hat Red Hat Enterprise Linux 6

    • all versionsunknown

  • Red Hat Red Hat Enterprise Linux 7

    • all versionsunknown
    • all versionsunknown

  • Red Hat Red Hat Enterprise Linux 8

    • 0:4.18.0-513.24.1.rt7.326.el8_9 and laternot affected · rpm
    • 0:4.18.0-513.24.1.el8_9 and laternot affected · rpm
    • all versionsunknown

  • Red Hat Red Hat Enterprise Linux 8.2 Advanced Update Support

    • 0:4.18.0-193.136.1.el8_2 and laternot affected · rpm

  • Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support

    • 0:4.18.0-305.134.1.el8_4 and laternot affected · rpm

  • Red Hat Red Hat Enterprise Linux 8.4 Telecommunications Update Service

    • 0:4.18.0-305.134.1.rt7.210.el8_4 and laternot affected · rpm
    • 0:4.18.0-305.134.1.el8_4 and laternot affected · rpm

  • Red Hat Red Hat Enterprise Linux 8.4 Update Services for SAP Solutions

    • 0:4.18.0-305.134.1.el8_4 and laternot affected · rpm
    • all versionsunknown

  • Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support

    • 0:4.18.0-372.93.1.el8_6 and laternot affected · rpm
    • all versionsunknown

  • Red Hat Red Hat Enterprise Linux 8.8 Extended Update Support

    • 0:4.18.0-477.55.1.el8_8 and laternot affected · rpm
    • all versionsunknown

  • Red Hat Red Hat Enterprise Linux 9

    • 0:5.14.0-427.13.1.el9_4 and laternot affected · rpm
    • 0:5.14.0-427.13.1.el9_4 and laternot affected · rpm
    • all versionsaffected

  • Red Hat Red Hat Enterprise Linux 9.0 Extended Update Support

    • 0:5.14.0-70.93.2.el9_0 and laternot affected · rpm
    • 0:5.14.0-70.93.1.rt21.165.el9_0 and laternot affected · rpm
    • all versionsunknown

  • Red Hat Red Hat Enterprise Linux 9.2 Extended Update Support

    • 0:5.14.0-284.55.1.el9_2 and laternot affected · rpm
    • 0:5.14.0-284.55.1.rt14.340.el9_2 and laternot affected · rpm
    • all versionsunknown

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:8bpftoolbefore 4.18.0-513.24.1.el8_94.18.0-513.24.1.el8_9
AlmaLinux:8kernelbefore 4.18.0-513.24.1.el8_94.18.0-513.24.1.el8_9
AlmaLinux:8kernel-abi-stablelistsbefore 4.18.0-513.24.1.el8_94.18.0-513.24.1.el8_9
AlmaLinux:8kernel-corebefore 4.18.0-513.24.1.el8_94.18.0-513.24.1.el8_9
AlmaLinux:8kernel-cross-headersbefore 4.18.0-513.24.1.el8_94.18.0-513.24.1.el8_9
AlmaLinux:8kernel-debugbefore 4.18.0-513.24.1.el8_94.18.0-513.24.1.el8_9
AlmaLinux:8kernel-debug-corebefore 4.18.0-513.24.1.el8_94.18.0-513.24.1.el8_9
AlmaLinux:8kernel-debug-develbefore 4.18.0-513.24.1.el8_94.18.0-513.24.1.el8_9
AlmaLinux:8kernel-debug-modulesbefore 4.18.0-513.24.1.el8_94.18.0-513.24.1.el8_9
AlmaLinux:8kernel-debug-modules-extrabefore 4.18.0-513.24.1.el8_94.18.0-513.24.1.el8_9
AlmaLinux:8kernel-develbefore 4.18.0-513.24.1.el8_94.18.0-513.24.1.el8_9
AlmaLinux:8kernel-docbefore 4.18.0-513.24.1.el8_94.18.0-513.24.1.el8_9
AlmaLinux:8kernel-modulesbefore 4.18.0-513.24.1.el8_94.18.0-513.24.1.el8_9
AlmaLinux:8kernel-modules-extrabefore 4.18.0-513.24.1.el8_94.18.0-513.24.1.el8_9
AlmaLinux:8kernel-toolsbefore 4.18.0-513.24.1.el8_94.18.0-513.24.1.el8_9
AlmaLinux:8kernel-tools-libsbefore 4.18.0-513.24.1.el8_94.18.0-513.24.1.el8_9
AlmaLinux:8kernel-tools-libs-develbefore 4.18.0-513.24.1.el8_94.18.0-513.24.1.el8_9
AlmaLinux:8kernel-zfcpdumpbefore 4.18.0-513.24.1.el8_94.18.0-513.24.1.el8_9
AlmaLinux:8kernel-zfcpdump-corebefore 4.18.0-513.24.1.el8_94.18.0-513.24.1.el8_9
AlmaLinux:8kernel-zfcpdump-develbefore 4.18.0-513.24.1.el8_94.18.0-513.24.1.el8_9
AlmaLinux:8kernel-zfcpdump-modulesbefore 4.18.0-513.24.1.el8_94.18.0-513.24.1.el8_9
AlmaLinux:8kernel-zfcpdump-modules-extrabefore 4.18.0-513.24.1.el8_94.18.0-513.24.1.el8_9
AlmaLinux:8perfbefore 4.18.0-513.24.1.el8_94.18.0-513.24.1.el8_9
AlmaLinux:8python3-perfbefore 4.18.0-513.24.1.el8_94.18.0-513.24.1.el8_9

+96

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now
  • CVE-2016-5195Race condition in mm/gup.c in the Linux kernel 2.x through 4.x before 4.8.3 allows local users to gain privileges by leveraging incorrect haKEV
    83Now

Published before and after this one in the same product

  • ← EarlierCVE-2023-6931Dec 19, 2023 · Out-of-bounds write in Linux kernel's Performance Events system component
    28Monitor
  • ← EarlierCVE-2023-6932Dec 19, 2023 · Use-after-free in Linux kernel's ipv4: igmp component
    28Monitor
  • Later →CVE-2023-7042Dec 21, 2023 · Kernel: null pointer dereference in ath10k_wmi_tlv_op_pull_mgmt_tx_compl_ev()
    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
almalinux:bpftool4.18.0-513.24.1.el8_9 · AlmaLinux:8Package registry (OSV)
almalinux:kernel4.18.0-513.24.1.el8_9 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-abi-stablelists4.18.0-513.24.1.el8_9 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-core4.18.0-513.24.1.el8_9 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-cross-headers4.18.0-513.24.1.el8_9 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug4.18.0-513.24.1.el8_9 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-core4.18.0-513.24.1.el8_9 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-devel4.18.0-513.24.1.el8_9 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules4.18.0-513.24.1.el8_9 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules-extra4.18.0-513.24.1.el8_9 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-devel4.18.0-513.24.1.el8_9 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-doc4.18.0-513.24.1.el8_9 · AlmaLinux:8Package registry (OSV)
debian:linux6.1.52-1 · Debian:12Package registry (OSV)
opensuse:kernel-rt5.14.21-150500.13.30.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-rt_debug5.14.21-150500.13.30.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-source-rt5.14.21-150500.13.30.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:kernel-syms-rt5.14.21-150500.13.30.1 · openSUSE:Leap 15.5Package registry (OSV)
red hat:bpftool0:4.18.0-372.93.1.el8_6 · Red Hat:rhel_eus:8.6::baseosPackage registry (OSV)
red hat:bpftool-debuginfo0:4.18.0-372.93.1.el8_6 · Red Hat:rhev_hypervisor:4.4::el8Package registry (OSV)
red hat:kernel0:4.18.0-372.93.1.el8_6 · Red Hat:rhel_eus:8.6::baseosPackage registry (OSV)
red hat:kernel-abi-stablelists0:4.18.0-372.93.1.el8_6 · Red Hat:rhel_eus:8.6::baseosPackage registry (OSV)
red hat:kernel-debug-debuginfo0:4.18.0-372.93.1.el8_6 · Red Hat:rhev_hypervisor:4.4::el8Package registry (OSV)
red hat:kernel-debuginfo0:4.18.0-372.93.1.el8_6 · Red Hat:rhev_hypervisor:4.4::el8Package registry (OSV)
red hat:kernel-debuginfo-common-x86_640:4.18.0-372.93.1.el8_6 · Red Hat:rhev_hypervisor:4.4::el8Package registry (OSV)
red hat:kernel-devel0:4.18.0-372.93.1.el8_6 · Red Hat:rhev_hypervisor:4.4::el8Package registry (OSV)
red hat:kernel-tools-debuginfo0:4.18.0-372.93.1.el8_6 · Red Hat:rhev_hypervisor:4.4::el8Package registry (OSV)
red hat:perf0:4.18.0-372.93.1.el8_6 · Red Hat:rhev_hypervisor:4.4::el8Package registry (OSV)
red hat:perf-debuginfo0:4.18.0-372.93.1.el8_6 · Red Hat:rhev_hypervisor:4.4::el8Package registry (OSV)
red hat:python3-perf-debuginfo0:4.18.0-372.93.1.el8_6 · Red Hat:rhev_hypervisor:4.4::el8Package registry (OSV)
rocky linux:kernel0:4.18.0-513.24.1.el8_9 · Rocky Linux:8Package registry (OSV)

+9

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:12025-02-01

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.

  1. Published
  2. First PoC+407 d
  3. TodayOct 20, 2026+1033 d
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.

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-2022-1729476 days apartA race condition was found the Linux kernel in perf_event_open() which can be exploited by an unprivileged user to gain root privileges.
    28Monitor
  • CVE-2023-473279 days apartKernel: race between task migrating pages and another task calling exit_mmap to release those same pages getting invalid opcode bug in include/linux/swapops.h
    18Monitor

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.
  • A low-privileged account is enough.
  • No user action is required.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
High
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-366 · Race Condition within a Thread

CVSS vector

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

nvd-primary

Attack context

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

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

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

References

Show all references (19 more)

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

All records