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TI-2023-03895 Aliases CVE-2023-4207GHSA-4fhg-56x9-rf4r

Use-after-free in Linux kernel's net/sched: cls_fw component

Priority LOW 34CWE-416Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 29 fixed, 1 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.

Summary

A use-after-free vulnerability in the Linux kernel's net/sched: cls_fw component can be exploited to achieve local privilege escalation. When fw_change() is called on an existing filter, the whole tcf_result struct is always copied into the new instance of the filter. This causes a problem when updating a filter bound to a class, as tcf_unbind_filter() is always called on the old instance in the success path, decreasing filter_cnt of the still referenced class and allowing it to be deleted, leading to a use-after-free. We recommend upgrading past commit 76e42ae831991c828cffa8c37736ebfb831ad5ec.

Why it matters now

EPSS 0.00313 24th percentileScored 2026-11-07
Fix Partial Kernel (Linux): 6.5Red Hat: 13 advisoriesRed Hat: 29 fixed, 1 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxKernel3.18 to before 6.56.5Patch availableCNA
  • Kernel VendorLinux Affected 3.18 to before 6.5 Fixed in 6.5 Patch available CNA

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*3.18 to before 4.14.326; 4.15 to before 4.19.295; 4.20 to before 5.4.253; 5.5 to before 5.10.190; 5.11 to before 5.15.126; 5.16 to before 6.1.45; 6.2 to before 6.4.10VulnerableLinux
cpe:2.3:o:debian:debian_linux:12.0:*:*:*:*:*:*:*12.0VulnerableDebian
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 3.18 to before 4.14.326; 4.15 to before 4.19.295; 4.20 to before 5.4.253; 5.5 to before 5.10.190; 5.11 to before 5.15.126; 5.16 to before 6.1.45; 6.2 to before 6.4.10 Vulnerable ·Linux
  • cpe:2.3:o:debian:debian_linux:12.0:*:*:*:*:*:*:* Versions 12.0 Vulnerable ·Debian

Remediation

  • Fix · CNA Kernel (Linux) Fixed in 6.5

Red Hat 13 advisories

  • RHSA-2024:0262 Released 2024-01-16 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux Server AUS (v. 7.7) bpftool-3.10.0-1062.82.1.el7, kernel-3.10.0-1062.82.1.el7, kernel-abi-whitelists-3.10.0-1062.82.1.el7 +8
    • Red Hat Enterprise Linux Server Optional AUS (v. 7.7) kernel-tools-libs-devel-3.10.0-1062.82.1.el7
  • RHSA-2024:0261 Released 2024-01-16 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux Server AUS (v. 7.6) bpftool-3.10.0-957.109.1.el7, kernel-3.10.0-957.109.1.el7, kernel-abi-whitelists-3.10.0-957.109.1.el7 +8
    • Red Hat Enterprise Linux Server Optional AUS (v. 7.6) kernel-tools-libs-devel-3.10.0-957.109.1.el7
  • RHSA-2023:7558 Released 2023-11-28 · Red Hat rating Important
    kpatch-patch security update
    • Red Hat Enterprise Linux BaseOS EUS (v.8.8) kpatch-patch-4_18_0-477_10_1-1-4.el8_8, kpatch-patch-4_18_0-477_13_1-1-3.el8_8, kpatch-patch-4_18_0-477_15_1-1-3.el8_8 +2
Show 10 more Red Hat advisories
  • RHSA-2023:7539 Released 2023-11-28 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat CodeReady Linux Builder EUS (v.8.8) kernel-tools-libs-devel-4.18.0-477.36.1.el8_8
    • Red Hat Enterprise Linux BaseOS EUS (v.8.8) bpftool-4.18.0-477.36.1.el8_8, kernel-4.18.0-477.36.1.el8_8, kernel-abi-stablelists-4.18.0-477.36.1.el8_8 +19
  • RHSA-2023:7423 Released 2023-11-21 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux Client (v. 7) bpftool-3.10.0-1160.105.1.el7, kernel-3.10.0-1160.105.1.el7, kernel-abi-whitelists-3.10.0-1160.105.1.el7 +8
    • Red Hat Enterprise Linux Client Optional (v. 7) kernel-tools-libs-devel-3.10.0-1160.105.1.el7
    • Red Hat Enterprise Linux ComputeNode Optional (v. 7) kernel-tools-libs-devel-3.10.0-1160.105.1.el7
    • Red Hat Enterprise Linux Server (v. 7) bpftool-3.10.0-1160.105.1.el7, kernel-3.10.0-1160.105.1.el7, kernel-abi-whitelists-3.10.0-1160.105.1.el7 +11
    • Red Hat Enterprise Linux Server Optional (v. 7) kernel-debug-devel-3.10.0-1160.105.1.el7, kernel-tools-libs-devel-3.10.0-1160.105.1.el7
    • Red Hat Enterprise Linux Workstation (v. 7) bpftool-3.10.0-1160.105.1.el7, kernel-3.10.0-1160.105.1.el7, kernel-abi-whitelists-3.10.0-1160.105.1.el7 +8
    • Red Hat Enterprise Linux Workstation Optional (v. 7) kernel-tools-libs-devel-3.10.0-1160.105.1.el7
  • RHSA-2023:7419 Released 2023-11-21 · Red Hat rating Important
    kpatch-patch security update
    • Red Hat Enterprise Linux Server (v. 7) kpatch-patch-3_10_0-1160_102_1-1-1.el7, kpatch-patch-3_10_0-1160_90_1-1-4.el7, kpatch-patch-3_10_0-1160_92_1-1-4.el7 +2
  • RHSA-2023:7424 Released 2023-11-21 · Red Hat rating Important
    kernel-rt security update
    • Red Hat Enterprise Linux for Real Time (v. 7) kernel-rt-3.10.0-1160.105.1.rt56.1256.el7, kernel-rt-debug-3.10.0-1160.105.1.rt56.1256.el7, kernel-rt-debug-devel-3.10.0-1160.105.1.rt56.1256.el7 +4
    • Red Hat Enterprise Linux for Real Time for NFV (v. 7) kernel-rt-3.10.0-1160.105.1.rt56.1256.el7, kernel-rt-debug-3.10.0-1160.105.1.rt56.1256.el7, kernel-rt-debug-devel-3.10.0-1160.105.1.rt56.1256.el7 +7
  • RHSA-2023:7418 Released 2023-11-21 · Red Hat rating Important
    kpatch-patch security update
    • Red Hat Enterprise Linux BaseOS EUS (v.9.2) kpatch-patch-5_14_0-284_11_1-1-6.el9_2, kpatch-patch-5_14_0-284_18_1-1-5.el9_2, kpatch-patch-5_14_0-284_25_1-1-4.el9_2 +1
  • RHSA-2023:7370 Released 2023-11-21 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat CodeReady Linux Builder EUS (v.9.2) kernel-tools-libs-devel-5.14.0-284.40.1.el9_2
    • Red Hat Enterprise Linux AppStream EUS (v.9.2) kernel-64k-debug-devel-5.14.0-284.40.1.el9_2, kernel-64k-debug-devel-matched-5.14.0-284.40.1.el9_2, kernel-64k-devel-5.14.0-284.40.1.el9_2 +10
    • Red Hat Enterprise Linux BaseOS EUS (v.9.2) bpftool-7.0.0-284.40.1.el9_2, kernel-5.14.0-284.40.1.el9_2, kernel-64k-5.14.0-284.40.1.el9_2 +29
  • RHSA-2023:7379 Released 2023-11-21 · Red Hat rating Important
    kernel-rt security update
    • Red Hat Enterprise Linux Real Time EUS (v.9.2) kernel-rt-5.14.0-284.40.1.rt14.325.el9_2, kernel-rt-core-5.14.0-284.40.1.rt14.325.el9_2, kernel-rt-debug-5.14.0-284.40.1.rt14.325.el9_2 +9
    • Red Hat Enterprise Linux Real Time for NFV EUS (v.9.2) kernel-rt-5.14.0-284.40.1.rt14.325.el9_2, kernel-rt-core-5.14.0-284.40.1.rt14.325.el9_2, kernel-rt-debug-5.14.0-284.40.1.rt14.325.el9_2 +11
  • RHSA-2023:7077 Released 2023-11-14 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat CodeReady Linux Builder (v. 8) kernel-tools-libs-devel-4.18.0-513.5.1.el8_9
    • Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-513.5.1.el8_9, kernel-4.18.0-513.5.1.el8_9, kernel-abi-stablelists-4.18.0-513.5.1.el8_9 +19
  • RHSA-2023:6901 Released 2023-11-14 · Red Hat rating Important
    kernel-rt security, bug fix, and enhancement update
    • Red Hat Enterprise Linux Real Time (v. 8) kernel-rt-4.18.0-513.5.1.rt7.307.el8_9, kernel-rt-core-4.18.0-513.5.1.rt7.307.el8_9, kernel-rt-debug-4.18.0-513.5.1.rt7.307.el8_9 +7
    • Red Hat Enterprise Linux Real Time for NFV (v. 8) kernel-rt-4.18.0-513.5.1.rt7.307.el8_9, kernel-rt-core-4.18.0-513.5.1.rt7.307.el8_9, kernel-rt-debug-4.18.0-513.5.1.rt7.307.el8_9 +9
  • RHSA-2023:6583 Released 2023-11-07 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-362.8.1.el9_3, libperf-5.14.0-362.8.1.el9_3
    • Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-362.8.1.el9_3, kernel-64k-debug-devel-matched-5.14.0-362.8.1.el9_3, kernel-64k-devel-5.14.0-362.8.1.el9_3 +11
    • Red Hat Enterprise Linux BaseOS (v. 9) bpftool-7.2.0-362.8.1.el9_3, kernel-5.14.0-362.8.1.el9_3, kernel-64k-5.14.0-362.8.1.el9_3 +29
    • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-362.8.1.el9_3, kernel-rt-core-5.14.0-362.8.1.el9_3, kernel-rt-debug-5.14.0-362.8.1.el9_3 +9
    • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-362.8.1.el9_3, kernel-rt-core-5.14.0-362.8.1.el9_3, kernel-rt-debug-5.14.0-362.8.1.el9_3 +11

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 9AffectedNo fix yet
Red Hat CodeReady Linux Builder (v. 8)Fixed RHSA-2023:7077
Red Hat CodeReady Linux Builder (v. 9)Fixed RHSA-2023:6583
Red Hat CodeReady Linux Builder EUS (v.8.8)Fixed RHSA-2023:7539
Red Hat CodeReady Linux Builder EUS (v.9.2)Fixed RHSA-2023:7370
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2023:6583
Red Hat Enterprise Linux AppStream EUS (v.9.2)Fixed RHSA-2023:7370
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2023:7077
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2023:6583
Red Hat Enterprise Linux BaseOS EUS (v.8.8)Fixed RHSA-2023:7539, RHSA-2023:7558
Red Hat Enterprise Linux BaseOS EUS (v.9.2)Fixed RHSA-2023:7370, RHSA-2023:7418
Red Hat Enterprise Linux Client (v. 7)Fixed RHSA-2023:7423
Red Hat Enterprise Linux Client Optional (v. 7)Fixed RHSA-2023:7423
Red Hat Enterprise Linux ComputeNode Optional (v. 7)Fixed RHSA-2023:7423
Red Hat Enterprise Linux Real Time (v. 8)Fixed RHSA-2023:6901
Red Hat Enterprise Linux Real Time (v. 9)Fixed RHSA-2023:6583
Red Hat Enterprise Linux Real Time EUS (v.9.2)Fixed RHSA-2023:7379
Red Hat Enterprise Linux Real Time for NFV (v. 8)Fixed RHSA-2023:6901
Red Hat Enterprise Linux Real Time for NFV (v. 9)Fixed RHSA-2023:6583
Red Hat Enterprise Linux Real Time for NFV EUS (v.9.2)Fixed RHSA-2023:7379
Red Hat Enterprise Linux Server (v. 7)Fixed RHSA-2023:7419, RHSA-2023:7423
Red Hat Enterprise Linux Server AUS (v. 7.6)Fixed RHSA-2024:0261
Red Hat Enterprise Linux Server AUS (v. 7.7)Fixed RHSA-2024:0262
Red Hat Enterprise Linux Server Optional (v. 7)Fixed RHSA-2023:7423
Red Hat Enterprise Linux Server Optional AUS (v. 7.6)Fixed RHSA-2024:0261
Red Hat Enterprise Linux Server Optional AUS (v. 7.7)Fixed RHSA-2024:0262
Red Hat Enterprise Linux Workstation (v. 7)Fixed RHSA-2023:7423
Red Hat Enterprise Linux Workstation Optional (v. 7)Fixed RHSA-2023:7423
Red Hat Enterprise Linux for Real Time (v. 7)Fixed RHSA-2023:7424
Red Hat Enterprise Linux for Real Time for NFV (v. 7)Fixed RHSA-2023:7424
Not affected: 2 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux AppStream EUS (v.9.2)

Timeline

  1. 2026-10-02 Threatist record created from CVE-2023-4207
  2. 2026-10-03 Alias added: GHSA-4fhg-56x9-rf4r

References

Patch 2

Advisory 2

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
  • TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
See all 15278 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences