CVE-2018-20685: fix a vulnerability scp client where a malicious server
could bypass intended access restrictions and modify target directory
permissions via crafted filenames
CVE-2019-6109: fix scp client where a malicious server could manipulate
the client's progress display output due to missing character encoding
CVE-2019-6111: fix scp client vulnerability that allowed a malicious
server to overwrite arbitrary files in the client's target directory,
including subdirectories, when performing transfers