CVE-2021-47408
kernel: netfilter: conntrack: serialize hash resizes and cleanups
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · May 21, 2024
Updated · June 28, 2026
Description
A vulnerability was found in the Linux kernel’s netfilter and conntrack module, occurring during the resizing and cleanup of hash tables used for connection tracking. The kernel's nf_ct_iterate_cleanup() function fails to efficiently handle simultaneous hash resizes and cleanups, leading to prolonged delays lead to unresponsive system behavior.
Statement
This vulnerability is rated as a moderate severity because it impacts on system availability rather than data security, affects system performance and responsiveness, particularly during cleanup operations under high load conditions
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
Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.
CVSS / CWE
CVSS 3.1 · 4.7CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE-667 · Improper Locking