A quote cwd command on FTP servers can reveal the full path of the home directory of the "ftp" user.
https://www.cve.org/CVERecord?id=CVE-1999-0201
Source: Mitre, NVD
Published: 1997-01-01
Updated: 2022-08-17
Base Score: 6.4
Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:N
Severity: Medium
Base Score: 7.5
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Severity: High