CVE-2021-20219
kernel: improper synchronization in flush_to_ldisc() can lead to DoS
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · May 26, 2018
Updated · June 28, 2026
Description
A denial of service vulnerability was found in n_tty_receive_char_special in drivers/tty/n_tty.c of the Linux kernel. In this flaw a local attacker with a normal user privilege could delay the loop (due to a changing ldata->read_head, and a missing sanity check) and cause a threat to the system availability.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
CVSS / CWE
CVSS 3.1 · 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE-697 · Incorrect Comparison