Use After Free in Linux

CVE-2021-47356

In the Linux kernel, the following vulnerability has been resolved: mISDN: fix possible use-after-free in HFC_cleanup() This module's remove path calls del_timer(). However, that function does not wait until the timer handler finishes. This means that the timer handler may still be running after the driver's remove function has finished, which would result in a use-after-free. Fix by calling del_timer_sync(), which makes sure the timer handler has finished, and unable to re-schedule itself.

Vulnerability class: Use-After-Free

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.7 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H.

EPSS exploit prediction

EPSS: 0.003 (17.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 17th percentile — 17.2% 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-2021-47356: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-47356?
CVE-2021-47356 is a high-severity vulnerability in Linux, classified under Use After Free. CVSS score: 7.7/10. Published 2024-05-21.
How severe is CVE-2021-47356?
High severity. CVSS v3 base score is 7.7 out of 10.