[2.3.0] Checkmk Werk 15200 created: Restrict check_sftp local paths

[//]: # (werk v2) # Restrict check_sftp local paths key | value ---------- | --- date | 2024-05-16T09:48:20+00:00 version | 2.3.0p4 class | security edition | cre component | checks level | 1 compatible | no Prior to this Werk, `check_sftp` did not restrict the local paths that for files to be uploaded and downloaded. This allowed users with the permissions to configure `check_sftp` to read or write files within the Checkmk site home. The local paths are now restricted to the folder `var/check_mk/active_checks/check_sftp` within the Checkmk site home. As a consequence, the local paths in existing configurations will now be interpreted as relative to that folder. Since a test file is created if the local file to upload doesn't exist, the check will continue to work, but it will not pick up files from the old location. Similarly, the downloaded files will be stored in a new location. This issue was found during internal review. *Affected Versions*: * 2.3.0 * 2.2.0 * 2.1.0 * 2.0.0 (EOL) *Vulnerability Management*: We have rated the issue with a CVSS Score of 8.8 High with the following CVSS vector: `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H` and assigned CVE `CVE-2024-28826`.