An issue was discovered in OpenSSH 7.9. Due to the scp implementation being derived from 1983 rcp the server chooses which files/directories are sent to the client. However the scp client only performs cursory validation of the object name returned (only directory traversal attacks are prevented). A malicious scp server (or Man-in-The-Middle attacker) can overwrite arbitrary files in the scp client target directory. If recursive operation (-r) is performed the server can manipulate subdirectories as well (for example to overwrite the .ssh/authorized_keys file).