Linux Kernel up to 4.19.198/5.4.135/5.10.53/5.13.5 Ethernet Packet tcf_skbmod_act privilege escalation

Summaryinfo

A vulnerability described as problematic has been identified in Linux Kernel up to 4.19.198/5.4.135/5.10.53/5.13.5. The impacted element is the function tcf_skbmod_act of the component Ethernet Packet Handler. Such manipulation leads to an unknown weakness. This vulnerability is uniquely identified as CVE-2021-47293. No exploit exists. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Linux Kernel up to 4.19.198/5.4.135/5.10.53/5.13.5. It has been rated as problematic. Affected by this issue is the function tcf_skbmod_act of the component Ethernet Packet Handler. The impact remains unknown. CVE summarizes:

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.

The advisory is available at git.kernel.org. This vulnerability is handled as CVE-2021-47293 since 05/21/2024. Technical details are known, but there is no available exploit.

Upgrading to version 4.19.199, 5.4.136, 5.10.54 or 5.13.6 eliminates this vulnerability. Applying the patch e4fdca366806/a88414fb1117/071729150be9/34f1e1f657fa/727d6a8b7ef3 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 4.19.198
• 5.4.135
• 5.10.0
• 5.10.1
• 5.10.2
• 5.10.3
• 5.10.4
• 5.10.5
• 5.10.6
• 5.10.7
• 5.10.8
• 5.10.9
• 5.10.10
• 5.10.11
• 5.10.12
• 5.10.13
• 5.10.14
• 5.10.15
• 5.10.16
• 5.10.17
• 5.10.18
• 5.10.19
• 5.10.20
• 5.10.21
• 5.10.22
• 5.10.23
• 5.10.24
• 5.10.25
• 5.10.26
• 5.10.27
• 5.10.28
• 5.10.29
• 5.10.30
• 5.10.31
• 5.10.32
• 5.10.33
• 5.10.34
• 5.10.35
• 5.10.36
• 5.10.37
• 5.10.38
• 5.10.39
• 5.10.40
• 5.10.41
• 5.10.42
• 5.10.43
• 5.10.44
• 5.10.45
• 5.10.46
• 5.10.47
• 5.10.48
• 5.10.49
• 5.10.50
• 5.10.51
• 5.10.52
• 5.10.53
• 5.13.0
• 5.13.1
• 5.13.2
• 5.13.3
• 5.13.4
• 5.13.5

License

• open-source

Website

• Vendor: https://www.kernel.org/

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