CVE-2021-47293

net/sched: act_skbmod: Skip non-Ethernet packets

Description

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 \ matchall action skbmod swap mac Doing the above silently corrupts all the packets. Do not perform skbmod actions for non-Ethernet packets.

7.8

CVSS

Severity: High

CVSS 3.1 •

EPSS 0.04%

Affected: Linux Linux

References

Link	Tags
https://git.kernel.org/stable/c/e4fdca366806f6bab374d1a95e626a10a3854b0c	patch
https://git.kernel.org/stable/c/a88414fb1117f2fe65fb88e45ba694e1d09d5024	patch
https://git.kernel.org/stable/c/071729150be9e1d1b851b70efb6d91ee9269d57b	patch
https://git.kernel.org/stable/c/34f1e1f657fae2891b485a3b2b95fe4d2aef9f0d	patch
https://git.kernel.org/stable/c/727d6a8b7ef3d25080fad228b2c4a1d4da5999c6	patch

Frequently Asked Questions

What is the severity of CVE-2021-47293?: CVE-2021-47293 has been scored as a high severity vulnerability.
How to fix CVE-2021-47293?: To fix CVE-2021-47293, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-47293 being actively exploited in the wild?: As for now, there are no information to confirm that CVE-2021-47293 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-47293?: CVE-2021-47293 affects Linux Linux, Linux Linux.

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