CVE-2021-4203
kernel: Race condition in races in sk_peer_pid and sk_peer_cred accesses
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · September 29, 2021
Updated · June 28, 2026
Description
A use-after-free read flaw was found in sock_getsockopt() in net/core/sock.c due to SO_PEERCRED and SO_PEERGROUPS race with listen() (and connect()) in the Linux kernel. In this flaw, an attacker with a user privileges may crash the system or leak internal kernel information.
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 · 5.8CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:L
CWE-366 · Race Condition within a Thread