Use After Free in Linux

CVE-2021-47239

In the Linux kernel, the following vulnerability has been resolved: net: usb: fix possible use-after-free in smsc75xx_bind The commit 46a8b29c6306 ("net: usb: fix memory leak in smsc75xx_bind") fails to clean up the work scheduled in smsc75xx_reset-> smsc75xx_set_multicast, which leads to use-after-free if the work is scheduled to start after the deallocation. In addition, this patch also removes a dangling pointer - dev->data[0]. This patch calls cancel_work_sync to cancel the scheduled work and set the dangling pointer to NULL.

Vulnerability class: Use-After-Free

EPSS: 0.002 (13.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

  • Linux — versions 200dbfcad8011e50c3cec269ed7b980836eeb1fa, 22c840596af0c09068b6cf948616e6496e59e07f, 9e6b8c1ff9d997e1fa16cbd2d60739adf6dc1bbc
  • Linux Linux_kernel

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-47239?
CVE-2021-47239 is a high-severity vulnerability in Linux, classified under Use After Free. CVSS score: 7.8/10. Published 2024-05-21.
How severe is CVE-2021-47239?
High severity. CVSS v3 base score is 7.8 out of 10.