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7.8
HIGH CVSS 3.1
CVE-2023-4623
Use-after-free in Linux kernel's net/sched: sch_hfsc (HFSC qdisc traffic control) component
Description

A use-after-free vulnerability in the Linux kernel's net/sched: sch_hfsc (HFSC qdisc traffic control) component can be exploited to achieve local privilege escalation. If a class with a link-sharing curve (i.e. with the HFSC_FSC flag set) has a parent without a link-sharing curve, then init_vf() will call vttree_insert() on the parent, but vttree_remove() will be skipped in update_vf(). This leaves a dangling pointer that can cause a use-after-free. We recommend upgrading past commit b3d26c5702c7d6c45456326e56d2ccf3f103e60f.

INFO

Published Date :

Sept. 6, 2023, 2:15 p.m.

Last Modified :

March 20, 2025, 4:59 p.m.

Remotely Exploit :

No

Source :

[email protected]
Affected Products

The following products are affected by CVE-2023-4623 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel
1 Debian debian_linux
: Total Affected Vendor : 2 | Products : 2
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH [email protected]
CVSS 3.1 HIGH [email protected]
Solution
This addresses a use-after-free vulnerability in the Linux kernel.
  • Update the kernel packages for your Linux distribution.
  • Reboot the system to apply the updated packages.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2023-4623.

URL Resource
http://packetstormsecurity.com/files/175963/Kernel-Live-Patch-Security-Notice-LSN-0099-1.html Third Party Advisory VDB Entry
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b3d26c5702c7d6c45456326e56d2ccf3f103e60f Issue Tracking Mailing List Patch Vendor Advisory
https://kernel.dance/b3d26c5702c7d6c45456326e56d2ccf3f103e60f Patch Vendor Advisory
https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html Mailing List Third Party Advisory
http://packetstormsecurity.com/files/175963/Kernel-Live-Patch-Security-Notice-LSN-0099-1.html Third Party Advisory VDB Entry
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b3d26c5702c7d6c45456326e56d2ccf3f103e60f Issue Tracking Mailing List Patch Vendor Advisory
https://kernel.dance/b3d26c5702c7d6c45456326e56d2ccf3f103e60f Patch Vendor Advisory
https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html Mailing List Third Party Advisory
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2023-4623 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2023-4623 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2023-4623 vulnerability anywhere in the article.

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2023-4623 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Modified Analysis by [email protected]

    Mar. 20, 2025

    Action Type Old Value New Value
  • CVE Modified by [email protected]

    Feb. 13, 2025

    Action Type Old Value New Value
    Changed Description A use-after-free vulnerability in the Linux kernel's net/sched: sch_hfsc (HFSC qdisc traffic control) component can be exploited to achieve local privilege escalation. If a class with a link-sharing curve (i.e. with the HFSC_FSC flag set) has a parent without a link-sharing curve, then init_vf() will call vttree_insert() on the parent, but vttree_remove() will be skipped in update_vf(). This leaves a dangling pointer that can cause a use-after-free. We recommend upgrading past commit b3d26c5702c7d6c45456326e56d2ccf3f103e60f. A use-after-free vulnerability in the Linux kernel's net/sched: sch_hfsc (HFSC qdisc traffic control) component can be exploited to achieve local privilege escalation. If a class with a link-sharing curve (i.e. with the HFSC_FSC flag set) has a parent without a link-sharing curve, then init_vf() will call vttree_insert() on the parent, but vttree_remove() will be skipped in update_vf(). This leaves a dangling pointer that can cause a use-after-free. We recommend upgrading past commit b3d26c5702c7d6c45456326e56d2ccf3f103e60f.
  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Nov. 21, 2024

    Action Type Old Value New Value
    Added Reference http://packetstormsecurity.com/files/175963/Kernel-Live-Patch-Security-Notice-LSN-0099-1.html
    Added Reference https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b3d26c5702c7d6c45456326e56d2ccf3f103e60f
    Added Reference https://kernel.dance/b3d26c5702c7d6c45456326e56d2ccf3f103e60f
    Added Reference https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html
    Added Reference https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html
  • Modified Analysis by [email protected]

    Aug. 26, 2024

    Action Type Old Value New Value
    Changed Reference Type http://packetstormsecurity.com/files/175963/Kernel-Live-Patch-Security-Notice-LSN-0099-1.html No Types Assigned http://packetstormsecurity.com/files/175963/Kernel-Live-Patch-Security-Notice-LSN-0099-1.html Third Party Advisory, VDB Entry
    Changed Reference Type https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html No Types Assigned https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html Mailing List, Third Party Advisory
    Changed CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 2.6.12 up to (excluding) 6.6 OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 2.6.12 up to (excluding) 4.14.327 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.15 up to (excluding) 4.19.295 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.20 up to (excluding) 5.4.257 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.5 up to (excluding) 5.10.195 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.15.132 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.16 up to (excluding) 6.1.53 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.4.16 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.5 up to (excluding) 6.5.3
  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • CVE Modified by [email protected]

    Jan. 11, 2024

    Action Type Old Value New Value
    Added Reference Google Inc. https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html [No types assigned]
  • CVE Modified by [email protected]

    Nov. 29, 2023

    Action Type Old Value New Value
    Added Reference Google Inc. http://packetstormsecurity.com/files/175963/Kernel-Live-Patch-Security-Notice-LSN-0099-1.html [No types assigned]
  • Modified Analysis by [email protected]

    Oct. 29, 2023

    Action Type Old Value New Value
    Changed Reference Type https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html No Types Assigned https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html Mailing List, Third Party Advisory
    Changed CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions up to (including) 2.5.75 *cpe:2.3:o:linux:linux_kernel:2.6.12:rc1:*:*:*:*:*:* OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 2.6.12 up to (excluding) 6.6
    Added CPE Configuration OR *cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
  • CVE Modified by [email protected]

    Oct. 20, 2023

    Action Type Old Value New Value
    Added Reference https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html [No Types Assigned]
  • Initial Analysis by [email protected]

    Sep. 11, 2023

    Action Type Old Value New Value
    Added CVSS V3.1 NIST AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
    Changed Reference Type https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b3d26c5702c7d6c45456326e56d2ccf3f103e60f No Types Assigned https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b3d26c5702c7d6c45456326e56d2ccf3f103e60f Issue Tracking, Mailing List, Patch, Vendor Advisory
    Changed Reference Type https://kernel.dance/b3d26c5702c7d6c45456326e56d2ccf3f103e60f No Types Assigned https://kernel.dance/b3d26c5702c7d6c45456326e56d2ccf3f103e60f Patch, Vendor Advisory
    Added CWE NIST CWE-416
    Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions up to (including) 2.5.75 *cpe:2.3:o:linux:linux_kernel:2.6.12:rc1:*:*:*:*:*:*
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
Base CVSS Score: 7.8
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact
Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

0.02 }} 0.00%

score

0.02393

percentile