Use After Free in Linux

CVE-2021-47668

In the Linux kernel, the following vulnerability has been resolved: can: dev: can_restart: fix use after free bug After calling netif_rx_ni(skb), dereferencing skb is unsafe. Especially, the can_frame cf which aliases skb memory is accessed after the netif_rx_ni() in: stats->rx_bytes += cf->len; Reordering the lines solves the issue.

Vulnerability class: Use-After-Free

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.002 (13.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 13th percentile — 13.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2021-47668: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000

Affected products

  • Linux — versions 39549eef3587f1c1e8c65c88a2400d10fd30ea17, 2.6.31, 0
  • Linux Kernel — versions 5.11

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-47668?
CVE-2021-47668 is a high-severity vulnerability in Linux, classified under Use After Free. CVSS score: 8.8/10. Published 2025-04-17.
How severe is CVE-2021-47668?
High severity. CVSS v3 base score is 8.8 out of 10.