Lucene search

K
redhatcveRedhat.comRH:CVE-2023-4623
HistorySep 07, 2023 - 7:35 a.m.

CVE-2023-4623

2023-09-0707:35:57
redhat.com
access.redhat.com
114
linux kernel
use-after-free
local privilege escalation
sch_hfsc
mitigation
module blacklisting

CVSS3

7.8

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

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

AI Score

7.4

Confidence

High

EPSS

0

Percentile

5.1%

A use-after-free flaw was found in the Linux kernel’s net/sched: sch_hfsc (HFSC qdisc traffic control) component that can be exploited to achieve local privilege escalation. If a class with a link-sharing curve, for example, 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 issue.

Mitigation

To mitigate this issue, prevent the module sch_hfsc from being loaded by blacklisting the module to prevent it from loading automatically.

https://access.redhat.com/solutions/41278   

CVSS3

7.8

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

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

AI Score

7.4

Confidence

High

EPSS

0

Percentile

5.1%