Select your cookie preferences

We use cookies and similar tools to enhance your experience, provide our services, deliver relevant advertising, and make improvements. Approved third parties also use these tools to help us deliver advertising and provide certain site features.

CVE-2023-4623

Public on 2023-09-06
Modified on 2024-01-12
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.

Severity
Important
See what this means
CVSS v3 Base Score
7.8
See breakdown
Continue reading

Affected Packages

Platform Package Release Date Advisory
Amazon Linux 1 kernel 2023-09-27 22:15 ALAS-2023-1838
Amazon Linux 2 - Core kernel 2023-09-27 22:48 ALAS2-2023-2264
Amazon Linux 2 - Kernel-5.10 Extra kernel 2023-09-27 22:59 ALAS2KERNEL-5.10-2023-040
Amazon Linux 2 - Kernel-5.15 Extra kernel 2023-09-27 22:59 ALAS2KERNEL-5.15-2023-027
Amazon Linux 2 - Kernel-5.4 Extra kernel 2023-09-27 22:59 ALAS2KERNEL-5.4-2023-053
Amazon Linux 2023 kernel 2023-09-27 21:04 ALAS2023-2023-356
Amazon Linux 2 - Livepatch Extra kernel-livepatch-4.14.320-243.544 2023-10-31 00:16 ALAS2LIVEPATCH-2023-154
Amazon Linux 2 - Livepatch Extra kernel-livepatch-4.14.322-244.536 2023-10-31 00:15 ALAS2LIVEPATCH-2023-152
Amazon Linux 2 - Livepatch Extra kernel-livepatch-4.14.322-244.539 2023-10-31 00:15 ALAS2LIVEPATCH-2023-153
Amazon Linux 2 - Livepatch Extra kernel-livepatch-4.14.322-246.539 2023-10-31 00:15 ALAS2LIVEPATCH-2023-151
Amazon Linux 2 - Livepatch Extra kernel-livepatch-5.10.186-179.751 2023-10-31 00:16 ALAS2LIVEPATCH-2023-155
Amazon Linux 2 - Livepatch Extra kernel-livepatch-5.10.192-182.736 2023-10-31 00:15 ALAS2LIVEPATCH-2023-150
Amazon Linux 2 - Livepatch Extra kernel-livepatch-5.10.192-183.736 2023-10-31 00:14 ALAS2LIVEPATCH-2023-149
Amazon Linux 2023 kernel-livepatch-6.1.49-69.116 2023-12-06 07:53 ALAS2023LIVEPATCH-2023-025
Amazon Linux 2023 kernel-livepatch-6.1.49-70.116 2023-12-06 07:53 ALAS2023LIVEPATCH-2023-026
Amazon Linux 2023 kernel-livepatch-6.1.52-71.125 2023-12-06 07:53 ALAS2023LIVEPATCH-2023-024

CVSS Scores

Score Type Score Vector
Amazon Linux CVSSv3 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD CVSSv3 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H