The product stores sensitive information in cleartext in a file, or on disk.
The sensitive information could be read by attackers with access to the file, or with physical or administrator access to the raw disk. 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.

Primary

Architecture and Design
OMISSION: This weakness is caused by missing a security tactic during the architecture and design phase.

Confidentiality
Read Application Data

Automated Static Analysis
Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)
High

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
...webapp.ldap.username=secretUsernamewebapp.ldap.password=secretPassword...

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.

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

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.

CVE-2001-1481
Cleartext credentials in world-readable file.
https://www.cve.org/CVERecord?id=CVE-2001-1481

CVE-2005-1828
Password in cleartext in config file.
https://www.cve.org/CVERecord?id=CVE-2005-1828

CVE-2005-2209
Password in cleartext in config file.
https://www.cve.org/CVERecord?id=CVE-2005-2209

CVE-2002-1696
Decrypted copy of a message written to disk given a combination of options and when user replies to an encrypted message.
https://www.cve.org/CVERecord?id=CVE-2002-1696

CVE-2004-2397
Cleartext storage of private key and passphrase in log file when user imports the key.
https://www.cve.org/CVERecord?id=CVE-2004-2397

Plaintext Storage in File or on Disk

SFP23
Exposed Data

Allowed
This CWE entry is at the Variant level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.
Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction.

Different people use "cleartext" and "plaintext" to mean the same thing: the lack of encryption. However, within cryptography, these have more precise meanings. Plaintext is the information just before it is fed into a cryptographic algorithm, including already-encrypted text. Cleartext is any information that is unencrypted, although it might be in an encoded form that is not easily human-readable (such as base64 encoding).

PLOVER
2006-07-19
Draft 3
2006-07-19

Eric Dalci
Cigital
2008-07-01
updated Time_of_Introduction

CWE Content Team
MITRE
2008-09-08
updated Relationships, Taxonomy_Mappings

CWE Content Team
MITRE
2010-12-13
updated Demonstrative_Examples

CWE Content Team
MITRE
2011-06-01
updated Common_Consequences

CWE Content Team
MITRE
2012-05-11
updated Demonstrative_Examples, Relationships

CWE Content Team
MITRE
2013-07-17
updated Applicable_Platforms, Demonstrative_Examples, Description, Name, Observed_Examples, Potential_Mitigations, Terminology_Notes

CWE Content Team
MITRE
2014-07-30
updated Relationships, Taxonomy_Mappings

CWE Content Team
MITRE
2017-11-08
updated Modes_of_Introduction, Relationships

CWE Content Team
MITRE
2020-02-24
updated Relationships

CWE Content Team
MITRE
2021-03-15
updated Demonstrative_Examples

CWE Content Team
MITRE
2021-10-28
updated Relationships

CWE Content Team
MITRE
2023-01-31
updated Description

CWE Content Team
MITRE
2023-04-27
updated Detection_Factors, Relationships

CWE Content Team
MITRE
2023-06-29
updated Mapping_Notes

CWE Content Team
MITRE
2025-12-11
4.19
2025-12-11
updated Relationships, Weakness_Ordinalities

Plaintext Storage in File or on Disk
Plaintext Storage in a File or on Disk