Cleartext Storage of Sensitive Information

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


Because the information is stored in cleartext (i.e., unencrypted), 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.

When organizations adopt cloud services, it can be easier for attackers to access the data from anywhere on the Internet.

In some systems/environments such as cloud, the use of "double encryption" (at both the software and hardware layer) might be required, and the developer might be solely responsible for both layers, instead of shared responsibility with the administrator of the broader system/environment.


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 cleartext.

This Java example shows a properties file with a cleartext 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 cleartext.

  <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 cleartext as this will allow anyone who can read the file access to the resource. If possible, encrypt this information.

Example Five

In 2022, the OT:ICEFALL study examined products by 10 different Operational Technology (OT) vendors. The researchers reported 56 vulnerabilities and said that the products were "insecure by design" [REF-1283]. If exploited, these vulnerabilities often allowed adversaries to change how the products operated, ranging from denial of service to changing the code that the products executed. Since these products were often used in industries such as power, electrical, water, and others, there could even be safety implications.

At least one OT product stored a password in plaintext.

Example Six

In 2021, a web site operated by PeopleGIS stored data of US municipalities in Amazon Web Service (AWS) Simple Storage Service (S3) buckets.

A security researcher found 86 S3 buckets that could be accessed without authentication (CWE-306) and stored data unencrypted (CWE-312). These buckets exposed over 1000 GB of data and 1.6 million files including physical addresses, phone numbers, tax documents, pictures of driver's license IDs, etc. [REF-1296] [REF-1295]

While it was not publicly disclosed how the data was protected after discovery, multiple options could have been considered.

The sensitive information could have been protected by ensuring that the buckets did not have public read access, e.g., by enabling the s3-account-level-public-access-blocks-periodic rule to Block Public Access. In addition, the data could have been encrypted at rest using the appropriate S3 settings, e.g., by enabling server-side encryption using the s3-bucket-server-side-encryption-enabled setting. Other settings are available to further prevent bucket data from being leaked. [REF-1297]

Example Seven

Consider the following PowerShell command examples for encryption scopes of Azure storage objects. In the first example, an encryption scope is set for the storage account.

New-AzStorageEncryptionScope -ResourceGroupName "MyResourceGroup" -AccountName "MyStorageAccount" -EncryptionScopeName testscope -StorageEncryption

The result (edited and formatted for readability) might be:

ResourceGroupName: MyResourceGroup, StorageAccountName: MyStorageAccount


However, the empty string under RequireInfrastructureEncryption indicates this service was not enabled at the time of creation, because the -RequireInfrastructureEncryption argument was not specified in the command.

Including the -RequireInfrastructureEncryption argument addresses the issue:

New-AzStorageEncryptionScope -ResourceGroupName "MyResourceGroup" -AccountName "MyStorageAccount" -EncryptionScopeName testscope -StorageEncryption -RequireInfrastructureEncryption

This produces the report:

ResourceGroupName: MyResourceGroup, StorageAccountName: MyStorageAccount


In a scenario where both software and hardware layer encryption is required ("double encryption"), Azure's infrastructure encryption setting can be enabled via the CLI or Portal. An important note is that infrastructure hardware encryption cannot be enabled or disabled after a blob is created. Furthermore, the default value for infrastructure encryption is disabled in blob creations.

See Also

Comprehensive Categorization: Encryption

Weaknesses in this category are related to encryption.

ICS Dependencies (& Architecture): External Digital Systems

Weaknesses in this category are related to the "External Digital Systems" category from the SEI ETF "Categories of Security Vulnerabilities in ICS" as published in Mar...

ICS Communications: Frail Security in Protocols

Weaknesses in this category are related to the "Frail Security in Protocols" category from the SEI ETF "Categories of Security Vulnerabilities in ICS" as published in ...

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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