A network administrator discovers several unknown files in the root directory of his Linux FTP server. One of
the files is a tarball, two are shell script files, and the third is a binary file is named “nc.” The FTP server’s
access logs show that the anonymous user account logged in to the server, uploaded the files, and extracted
the contents of the tarball and ran the script using a function provided by the FTP server’s software. The ps
command shows that the nc file is running as process, and the netstat command shows the nc process is
listening on a network port.
What kind of vulnerability must be present to make this remote attack possible?

A.
File system permissions

B.
Privilege escalation

C.
Directory traversal

D.
Brute force login

Explanation:
To upload files the user must have proper write file permissions.
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