Missing Encryption of Sensitive Data

Description

The lack of proper data encryption passes up the guarantees of confidentiality, integrity, and accountability that properly implemented encryption conveys.

Demonstrations

The following examples help to illustrate the nature of this weakness and describe methods or techniques which can be used to mitigate the risk.

Note that the examples here are by no means exhaustive and any given weakness may have many subtle varieties, each of which may require different detection methods or runtime controls.

Example One

This code writes a user's login information to a cookie so the user does not have to login again later.

function persistLogin($username, $password){
  $data = array("username" => $username, "password"=> $password);
  setcookie ("userdata", $data);
}

The code stores the user's username and password in plaintext in a cookie on the user's machine. This exposes the user's login information if their computer is compromised by an attacker. Even if the user's machine is not compromised, this weakness combined with cross-site scripting (CWE-79) could allow an attacker to remotely copy the cookie.

Also note this example code also exhibits Plaintext Storage in a Cookie (CWE-315).

Example Two

The following code attempts to establish a connection, read in a password, then store it to a buffer.

server.sin_family = AF_INET; hp = gethostbyname(argv[1]);
if (hp==NULL) error("Unknown host");
memcpy( (char *)&server.sin_addr,(char *)hp->h_addr,hp->h_length);
if (argc < 3) port = 80;
else port = (unsigned short)atoi(argv[3]);
server.sin_port = htons(port);
if (connect(sock, (struct sockaddr *)&server, sizeof server) < 0) error("Connecting");
...
while ((n=read(sock,buffer,BUFSIZE-1))!=-1) {


  write(dfd,password_buffer,n);
  ...

While successful, the program does not encrypt the data before writing it to a buffer, possibly exposing it to unauthorized actors.

Example Three

The following code attempts to establish a connection to a site to communicate sensitive information.

try {
  URL u = new URL("http://www.secret.example.org/");
  HttpURLConnection hu = (HttpURLConnection) u.openConnection();
  hu.setRequestMethod("PUT");
  hu.connect();
  OutputStream os = hu.getOutputStream();
  hu.disconnect();
}
catch (IOException e) {


  //...


}

Though a connection is successfully made, the connection is unencrypted and it is possible that all sensitive data sent to or received from the server will be read by unintended actors.

See Also