CVE-2021-47293
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.23%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.23% probability · 14th percentile
- CISA KEV
- Not listed
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/071729150be9e1d1b851b70efb6d91ee9269d57bPatch
- https://git.kernel.org/stable/c/34f1e1f657fae2891b485a3b2b95fe4d2aef9f0dPatch
- https://git.kernel.org/stable/c/727d6a8b7ef3d25080fad228b2c4a1d4da5999c6Patch
- https://git.kernel.org/stable/c/a88414fb1117f2fe65fb88e45ba694e1d09d5024Patch
- https://git.kernel.org/stable/c/e4fdca366806f6bab374d1a95e626a10a3854b0cPatch
- https://git.kernel.org/stable/c/071729150be9e1d1b851b70efb6d91ee9269d57bPatch
- https://git.kernel.org/stable/c/34f1e1f657fae2891b485a3b2b95fe4d2aef9f0dPatch
- https://git.kernel.org/stable/c/727d6a8b7ef3d25080fad228b2c4a1d4da5999c6Patch
- https://git.kernel.org/stable/c/a88414fb1117f2fe65fb88e45ba694e1d09d5024Patch
- https://git.kernel.org/stable/c/e4fdca366806f6bab374d1a95e626a10a3854b0cPatch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.