Cleartext Storage of Sensitive Information

The application stores sensitive information in cleartext within a resource that might be accessible to another control sphere.


Because the information is stored in cleartext, attackers could potentially read it. Even if the information is encoded in a way that is not human-readable, certain techniques could determine which encoding is being used, then decode the information.


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 excerpt stores a plaintext user account ID in a browser cookie.

response.addCookie( new Cookie("userAccountID", acctID);

Because the account ID is in plaintext, the user's account information is exposed if their computer is compromised by an attacker.

Example Two

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 Three

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) {


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

Example Four

The following examples show a portion of properties and configuration files for Java and ASP.NET applications. The files include username and password information but they are stored in plaintext.

This Java example shows a properties file with a plaintext username / password pair.

# Java Web App ResourceBundle properties file

The following example shows a portion of a configuration file for an ASP.Net application. This configuration file includes username and password information for a connection to a database but the pair is stored in plaintext.

  <add name="ud_DEV" connectionString="connectDB=uDB; uid=db2admin; pwd=password; dbalias=uDB;" providerName="System.Data.Odbc" />

Username and password information should not be included in a configuration file or a properties file in plaintext as this will allow anyone who can read the file access to the resource. If possible, encrypt this information and avoid CWE-260 and CWE-13.

See Also

OWASP Top Ten 2017 Category A3 - Sensitive Data Exposure

Weaknesses in this category are related to the A3 category in the OWASP Top Ten 2017.

Encrypt Data

Weaknesses in this category are related to the design and architecture of data confidentiality in a system. Frequently these deal with the use of encryption libraries....

SFP Secondary Cluster: Exposed Data

This category identifies Software Fault Patterns (SFPs) within the Exposed Data cluster (SFP23).

Comprehensive CWE Dictionary

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

Weaknesses in Mobile Applications

CWE entries in this view (slice) are often seen in mobile applications.

CWE Cross-section

This view contains a selection of weaknesses that represent the variety of weaknesses that are captured in CWE, at a level of abstraction that is likely to be useful t...

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