IM
IronMonkey Threat Research

CVE-2023-4623 HIGH

Published: 2023-09-06 | Last Modified: 2025-03-20 | Status: Analyzed

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.

Additional Descriptions (1)

Una vulnerabilidad de Use After Free en el componente net/sched: sch_hfsc (HFSC qdisc traffic control) del kernel de Linux puede ser explotada para conseguir una escalada local de privilegios. Si una clase con una curva de compartición de enlaces (es decir, con la flag HFSC_FSC establecida) tiene un padre sin una curva de compartición de enlaces, entonces init_vf() llamará a vttree_insert() en el padre, pero vttree_remove() se omitirá en update_vf(). Esto deja un puntero colgando que puede causar un Use-After-Free. Recomendamos actualizar desde el commit b3d26c5702c7d6c45456326e56d2ccf3f103e60f.

CVSS Metrics

Base Score: 7.8 (HIGH)

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

Attack VectorLOCAL
Attack ComplexityLOW
Privileges RequiredLOW
User InteractionNONE
ScopeUNCHANGED
Confidentiality ImpactHIGH
Integrity ImpactHIGH
Availability ImpactHIGH

Source: [email protected]

Type: Primary

Exploitability Score: 1.8

Impact Score: 5.9

Weaknesses

Source Type Description
[email protected] Secondary
en CWE-416
[email protected] Primary
en CWE-416

Affected Products

Vendor Product Version Update Type
linux linux_kernel * <built-in method update of dict object at 0x7fd384917fc0> Operating System
linux linux_kernel * <built-in method update of dict object at 0x7fd384914f80> Operating System
linux linux_kernel * <built-in method update of dict object at 0x7fd36ab76780> Operating System
linux linux_kernel * <built-in method update of dict object at 0x7fd3694e6ac0> Operating System
linux linux_kernel * <built-in method update of dict object at 0x7fd384914dc0> Operating System
linux linux_kernel * <built-in method update of dict object at 0x7fd384916440> Operating System
linux linux_kernel * <built-in method update of dict object at 0x7fd36be78b40> Operating System
linux linux_kernel * <built-in method update of dict object at 0x7fd384915dc0> Operating System
debian debian_linux 10.0 <built-in method update of dict object at 0x7fd384915a80> Operating System

Affected Configurations

Operator: OR

Vulnerable CPE
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

Operator: OR

Vulnerable CPE
Yes cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

References