CVE-2021-47293

net/sched: act_skbmod: Skip non-Ethernet packets

Severity Score

4.2

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

Track

*SSVC

Descriptions

In the Linux kernel, the following vulnerability has been resolved:

net/sched: act_skbmod: Skip non-Ethernet packets

Currently tcf_skbmod_act() assumes that packets use Ethernet as their L2
protocol, which is not always the case. As an example, for CAN devices:

$ ip link add dev vcan0 type vcan
$ ip link set up vcan0
$ tc qdisc add dev vcan0 root handle 1: htb
$ tc filter add dev vcan0 parent 1: protocol ip prio 10 \n matchall action skbmod swap mac

Doing the above silently corrupts all the packets. Do not perform skbmod
actions for non-Ethernet packets.

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: net/sched: act_skbmod: omitir paquetes que no sean Ethernet. Actualmente, tcf_skbmod_act() asume que los paquetes usan Ethernet como protocolo L2, lo cual no siempre es el caso. Como ejemplo, para dispositivos CAN: $ ip link add dev vcan0 type vcan $ ip link set up vcan0 $ tc qdisc add dev vcan0 root handle 1: htb $ tc filter add dev vcan0 parent 1: protocolo ip prio 10 \ matchall action skbmod swap mac Hacer lo anterior corrompe silenciosamente todos los paquetes. No realice acciones de skbmod para paquetes que no sean Ethernet.

*Credits: N/A

CVSS Scores

Red Hatv3.1 4.2

Attack Vector

Local

Attack Complexity

Low

Privileges Required

High

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

Low

Availability

Low

* Common Vulnerability Scoring System

SSVC

Decision:Track

Exploitation

None

Automatable

Tech. Impact

Partial

* Organization's Worst-case Scenario

Timeline

2024-05-21 CVE Reserved
2024-05-21 CVE Published
2024-05-22 EPSS Updated
2024-08-04 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-20: Improper Input Validation

CAPEC

References (8)

URL	Tag	Source
https://git.kernel.org/stable/c/86da71b57383d40993cb90baafb3735cffe5d800	Vuln. Introduced

URL	Date	SRC

URL	Date	SRC
https://git.kernel.org/stable/c/e4fdca366806f6bab374d1a95e626a10a3854b0c	2021-07-28
https://git.kernel.org/stable/c/a88414fb1117f2fe65fb88e45ba694e1d09d5024	2021-07-28
https://git.kernel.org/stable/c/071729150be9e1d1b851b70efb6d91ee9269d57b	2021-07-28
https://git.kernel.org/stable/c/34f1e1f657fae2891b485a3b2b95fe4d2aef9f0d	2021-07-28
https://git.kernel.org/stable/c/727d6a8b7ef3d25080fad228b2c4a1d4da5999c6	2021-07-20

URL	Date	SRC
https://access.redhat.com/security/cve/CVE-2021-47293	2024-07-10
https://bugzilla.redhat.com/show_bug.cgi?id=2282504	2024-07-10

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.9 < 4.19.199 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.9 < 4.19.199"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.9 < 5.4.136 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.9 < 5.4.136"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.9 < 5.10.54 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.9 < 5.10.54"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.9 < 5.13.6 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.9 < 5.13.6"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.9 < 5.14 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.9 < 5.14"		en		Affected