The Linux kernel before 5.17.9 allows TCP servers to identify clients by observing what source ports are used. This occurs because of use of Algorithm 4 ("Double-Hash Port Selection Algorithm") of RFC 6056.
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.17.9
https://lists.debian.org/debian-lts-announce/2022/07/msg00000.html
https://www.debian.org/security/2022/dsa-5173
Source: MITRE
Published: 2022-06-05
Updated: 2022-09-28
Type: CWE-203
Base Score: 2.1
Vector: AV:L/AC:L/Au:N/C:P/I:N/A:N
Impact Score: 2.9
Exploitability Score: 3.9
Severity: LOW
Base Score: 3.3
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Impact Score: 1.4
Exploitability Score: 1.8
Severity: LOW