Incorrect Resource Transfer Between Spheres

The product does not properly transfer a resource/behavior to another sphere, or improperly imports a resource/behavior from another sphere, in a manner that provides unintended control over that resource.


A "control sphere" is a set of resources and behaviors that are accessible to a single actor, or a group of actors. A product's security model will typically define multiple spheres, possibly implicitly. For example, a server might define one sphere for "administrators" who can create new user accounts with subdirectories under /home/server/, and a second sphere might cover the set of users who can create or delete files within their own subdirectories. A third sphere might be "users who are authenticated to the operating system on which the product is installed." Each sphere has different sets of actors and allowable behaviors.


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

The following code demonstrates the unrestricted upload of a file with a Java servlet and a path traversal vulnerability. The action attribute of an HTML form is sending the upload file request to the Java servlet.

<form action="FileUploadServlet" method="post" enctype="multipart/form-data">

Choose a file to upload:
<input type="file" name="filename"/>
<input type="submit" name="submit" value="Submit"/>


When submitted the Java servlet's doPost method will receive the request, extract the name of the file from the Http request header, read the file contents from the request and output the file to the local upload directory.

public class FileUploadServlet extends HttpServlet {


  protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    PrintWriter out = response.getWriter();
    String contentType = request.getContentType();

    // the starting position of the boundary header
    int ind = contentType.indexOf("boundary=");
    String boundary = contentType.substring(ind+9);

    String pLine = new String();
    String uploadLocation = new String(UPLOAD_DIRECTORY_STRING); //Constant value

    // verify that content type is multipart form data
    if (contentType != null && contentType.indexOf("multipart/form-data") != -1) {

      // extract the filename from the Http header
      BufferedReader br = new BufferedReader(new InputStreamReader(request.getInputStream()));
      pLine = br.readLine();
      String filename = pLine.substring(pLine.lastIndexOf("\\"), pLine.lastIndexOf("\""));

      // output the file to the local upload directory
      try {

        BufferedWriter bw = new BufferedWriter(new FileWriter(uploadLocation+filename, true));
        for (String line; (line=br.readLine())!=null; ) {
          if (line.indexOf(boundary) == -1) {
        } //end of for loop

      } catch (IOException ex) {...}
      // output successful upload response HTML page

    // output unsuccessful upload response HTML page



This code does not perform a check on the type of the file being uploaded (CWE-434). This could allow an attacker to upload any executable file or other file with malicious code.

Additionally, the creation of the BufferedWriter object is subject to relative path traversal (CWE-23). Since the code does not check the filename that is provided in the header, an attacker can use "../" sequences to write to files outside of the intended directory. Depending on the executing environment, the attacker may be able to specify arbitrary files to write to, leading to a wide variety of consequences, from code execution, XSS (CWE-79), or system crash.

Example Two

This code includes an external script to get database credentials, then authenticates a user against the database, allowing access to the application.

//assume the password is already encrypted, avoiding CWE-312

function authenticate($username,$password){


  //dbInfo.php makes $dbhost, $dbuser, $dbpass, $dbname available
  mysql_connect($dbhost, $dbuser, $dbpass) or die ('Error connecting to mysql');
  $query = 'Select * from users where username='.$username.' And password='.$password;
  $result = mysql_query($query);

  if(mysql_numrows($result) == 1){
    return true;
    return false;


This code does not verify that the external domain accessed is the intended one. An attacker may somehow cause the external domain name to resolve to an attack server, which would provide the information for a false database. The attacker may then steal the usernames and encrypted passwords from real user login attempts, or simply allow themself to access the application without a real user account.

This example is also vulnerable to an Adversary-in-the-Middle AITM (CWE-300) attack.

Example Three

This code either generates a public HTML user information page or a JSON response containing the same user information.

// API flag, output JSON if set
$json = $_GET['json']
$username = $_GET['user']

  $record = getUserRecord($username);
  foreach($record as $fieldName => $fieldValue)

    if($fieldName == "email_address") {

      // skip displaying user emails



  $record = getUserRecord($username);
  echo json_encode($record);

The programmer is careful to not display the user's e-mail address when displaying the public HTML page. However, the e-mail address is not removed from the JSON response, exposing the user's e-mail address.

See Also

Comprehensive Categorization: Resource Lifecycle Management

Weaknesses in this category are related to resource lifecycle management.

ICS Communications: Zone Boundary Failures

Weaknesses in this category are related to the "Zone Boundary Failures" category from the SEI ETF "Categories of Security Vulnerabilities in ICS" as published in March...

Authorize Actors

Weaknesses in this category are related to the design and architecture of a system's authorization components. Frequently these deal with enforcing that agents have th...

Comprehensive CWE Dictionary

This view (slice) covers all the elements in CWE.

Weaknesses for Simplified Mapping of Published Vulnerabilities

CWE entries in this view (graph) may be used to categorize potential weaknesses within sources that handle public, third-party vulnerability information, such as the N...

Weaknesses Introduced During Implementation

This view (slice) lists weaknesses that can be introduced during implementation.

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