The product generates an error message that includes sensitive information about its environment, users, or associated data.

Primary

Resultant

Architecture and Design

Implementation
REALIZATION: This weakness is caused during implementation of an architectural security tactic.

System Configuration

Operation

High

Confidentiality
Read Application Data
Often this will either reveal sensitive information which may be used to launch another, more focused attack or disclose private information stored in the server. For example, an attempt to exploit a path traversal weakness (CWE-22) might yield the full pathname of the installed application. In turn, this could be used to select the proper number of ".." sequences to navigate to the targeted file. An attack using SQL injection (CWE-89) might not initially succeed, but an error message could reveal the malformed query, which would expose query logic and possibly even passwords or other sensitive information used within the query.

Manual Analysis
This weakness generally requires domain-specific interpretation using manual analysis. However, the number of potential error conditions may be too large to cover completely within limited time constraints.
High

Automated Analysis
Automated methods may be able to detect certain idioms automatically, such as exposed stack traces or pathnames, but violation of business rules or privacy requirements is not typically feasible.
Moderate

Automated Dynamic Analysis

This weakness can be detected using dynamic tools and techniques that interact with the software using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The software's operation may slow down, but it should not become unstable, crash, or generate incorrect results.
Error conditions may be triggered with a stress-test by calling the software simultaneously from a large number of threads or processes, and look for evidence of any unexpected behavior.

Moderate

Manual Dynamic Analysis
Identify error conditions that are not likely to occur during normal usage and trigger them. For example, run the program under low memory conditions, run with insufficient privileges or permissions, interrupt a transaction before it is completed, or disable connectivity to basic network services such as DNS. Monitor the software for any unexpected behavior. If you trigger an unhandled exception or similar error that was discovered and handled by the application's environment, it may still indicate unexpected conditions that were not handled by the application itself.

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.)

Implementation

Ensure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended). The messages should not reveal the methods that were used to determine the error. Attackers can use detailed information to refine or optimize their original attack, thereby increasing their chances of success.
If errors must be captured in some detail, record them in log messages, but consider what could occur if the log messages can be viewed by attackers. Highly sensitive information such as passwords should never be saved to log files.
Avoid inconsistent messaging that might accidentally tip off an attacker about internal state, such as whether a user account exists or not.

Implementation
Handle exceptions internally and do not display errors containing potentially sensitive information to a user.

Implementation
Attack Surface Reduction
Use naming conventions and strong types to make it easier to spot when sensitive data is being used. When creating structures, objects, or other complex entities, separate the sensitive and non-sensitive data as much as possible.
Defense in Depth
This makes it easier to spot places in the code where data is being used that is unencrypted.

Implementation
Build and Compilation
Compilation or Build Hardening
Debugging information should not make its way into a production release.

Implementation
Build and Compilation
Environment Hardening
Debugging information should not make its way into a production release.

System Configuration
Where available, configure the environment to use less verbose error messages. For example, in PHP, disable the display_errors setting during configuration, or at runtime using the error_reporting() function.

System Configuration
Create default error pages or messages that do not leak any information.

In the following example, sensitive information might be printed depending on the exception that occurs.

try {/.../}catch (Exception e) {System.out.println(e);}

If an exception related to SQL is handled by the catch, then the output might contain sensitive information such as SQL query structure or private information. If this output is redirected to a web user, this may represent a security problem.

This code tries to open a database connection, and prints any exceptions that occur.

try {openDbConnection();}
//print exception message that includes exception message and configuration file location
catch (Exception $e) {echo 'Caught exception: ', $e->getMessage(), '\n';echo 'Check credentials in config file at: ', $Mysql_config_location, '\n';}

If an exception occurs, the printed message exposes the location of the configuration file the script is using. An attacker can use this information to target the configuration file (perhaps exploiting a Path Traversal weakness). If the file can be read, the attacker could gain credentials for accessing the database. The attacker may also be able to replace the file with a malicious one, causing the application to use an arbitrary database.

The following code generates an error message that leaks the full pathname of the configuration file.

$ConfigDir = "/home/myprog/config";$uname = GetUserInput("username");

# avoid CWE-22, CWE-78, others.
ExitError("Bad hacker!") if ($uname !~ /^\w+$/);$file = "$ConfigDir/$uname.txt";if (! (-e $file)) {ExitError("Error: $file does not exist");}...

If this code is running on a server, such as a web application, then the person making the request should not know what the full pathname of the configuration directory is. By submitting a username that does not produce a $file that exists, an attacker could get this pathname. It could then be used to exploit path traversal or symbolic link following problems that may exist elsewhere in the application.

In the example below, the method getUserBankAccount retrieves a bank account object from a database using the supplied username and account number to query the database. If an SQLException is raised when querying the database, an error message is created and output to a log file.

public BankAccount getUserBankAccount(String username, String accountNumber) {
BankAccount userAccount = null;String query = null;try {if (isAuthorizedUser(username)) {query = "SELECT * FROM accounts WHERE owner = "+ username + " AND accountID = " + accountNumber;DatabaseManager dbManager = new DatabaseManager();Connection conn = dbManager.getConnection();Statement stmt = conn.createStatement();ResultSet queryResult = stmt.executeQuery(query);userAccount = (BankAccount)queryResult.getObject(accountNumber);}} catch (SQLException ex) {String logMessage = "Unable to retrieve account information from database,\nquery: " + query;Logger.getLogger(BankManager.class.getName()).log(Level.SEVERE, logMessage, ex);}return userAccount;
}

The error message that is created includes information about the database query that may contain sensitive information about the database or query logic. In this case, the error message will expose the table name and column names used in the database. This data could be used to simplify other attacks, such as SQL injection (CWE-89) to directly access the database.

CVE-2008-2049
POP3 server reveals a password in an error message after multiple APOP commands are sent. Might be resultant from another weakness.
https://www.cve.org/CVERecord?id=CVE-2008-2049

CVE-2007-5172
Program reveals password in error message if attacker can trigger certain database errors.
https://www.cve.org/CVERecord?id=CVE-2007-5172

CVE-2008-4638
Composite: application running with high privileges (CWE-250) allows user to specify a restricted file to process, which generates a parsing error that leaks the contents of the file (CWE-209).
https://www.cve.org/CVERecord?id=CVE-2008-4638

CVE-2008-1579
Existence of user names can be determined by requesting a nonexistent blog and reading the error message.
https://www.cve.org/CVERecord?id=CVE-2008-1579

CVE-2007-1409
Direct request to library file in web application triggers pathname leak in error message.
https://www.cve.org/CVERecord?id=CVE-2007-1409

CVE-2008-3060
Malformed input to login page causes leak of full path when IMAP call fails.
https://www.cve.org/CVERecord?id=CVE-2008-3060

CVE-2005-0603
Malformed regexp syntax leads to information exposure in error message.
https://www.cve.org/CVERecord?id=CVE-2005-0603

CVE-2017-9615
verbose logging stores admin credentials in a world-readablelog file
https://www.cve.org/CVERecord?id=CVE-2017-9615

CVE-2018-1999036
SSH password for private key stored in build log
https://www.cve.org/CVERecord?id=CVE-2018-1999036

Accidental leaking of sensitive information through error messages

A6
Information Leakage and Improper Error Handling
CWE More Specific

A7
Improper Error Handling
CWE More Specific

A10
Insecure Configuration Management
CWE More Specific

ERR01-J
Do not allow exceptions to expose sensitive information

SFP23
Exposed Data

Allowed
This CWE entry is at the Base 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.

The sensitive information may be valuable information on its own (such as a password), or it may be useful for launching other, more serious attacks.
The error message may be created in different ways:

self-generated: the source code explicitly constructs the error message and delivers it
externally-generated: the external environment, such as a language interpreter, handles the error and constructs its own message, whose contents are not under direct control by the programmer

CLASP
2006-07-19
Draft 3
2006-07-19

Eric Dalci
Cigital
2008-07-01
updated Time_of_Introduction

Veracode
2008-08-15
Suggested OWASP Top Ten 2004 mapping

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

CWE Content Team
MITRE
2008-10-14
updated Relationships

CWE Content Team
MITRE
2009-01-12
updated Demonstrative_Examples, Description, Name, Observed_Examples, Other_Notes, Potential_Mitigations, Relationships, Time_of_Introduction

CWE Content Team
MITRE
2009-03-10
updated Demonstrative_Examples, Potential_Mitigations, Relationships

CWE Content Team
MITRE
2009-12-28
updated Demonstrative_Examples, Name, Potential_Mitigations, References, Time_of_Introduction

CWE Content Team
MITRE
2010-02-16
updated Detection_Factors, References, Relationships

CWE Content Team
MITRE
2010-04-05
updated Related_Attack_Patterns

CWE Content Team
MITRE
2010-06-21
updated Common_Consequences, Detection_Factors, Potential_Mitigations, References

Veracode
2010-09-09
Suggested OWASP Top Ten mapping

CWE Content Team
MITRE
2010-09-27
updated Potential_Mitigations, Relationships

CWE Content Team
MITRE
2011-03-29
updated Demonstrative_Examples, Observed_Examples, Relationships

CWE Content Team
MITRE
2011-06-01
updated Relationships, Taxonomy_Mappings

CWE Content Team
MITRE
2011-06-27
updated Relationships

CWE Content Team
MITRE
2011-09-13
updated Relationships, Taxonomy_Mappings

CWE Content Team
MITRE
2012-05-11
updated References, Related_Attack_Patterns, Relationships

CWE Content Team
MITRE
2013-07-17
updated References

CWE Content Team
MITRE
2014-06-23
updated Relationships

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

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

CWE Content Team
MITRE
2018-03-27
updated References, Relationships

CWE Content Team
MITRE
2019-01-03
updated Taxonomy_Mappings

CWE Content Team
MITRE
2019-06-20
updated Relationships

CWE Content Team
MITRE
2019-09-19
updated Demonstrative_Examples, Observed_Examples

CWE Content Team
MITRE
2020-02-24
updated Applicable_Platforms, Description, Name, Observed_Examples, References, Relationships, Weakness_Ordinalities

CWE Content Team
MITRE
2020-12-10
updated Potential_Mitigations, Related_Attack_Patterns

CWE Content Team
MITRE
2021-07-20
updated Relationships

CWE Content Team
MITRE
2021-10-28
updated Relationships

CWE Content Team
MITRE
2022-10-13
updated Demonstrative_Examples

CWE Content Team
MITRE
2023-01-31
updated Description

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

CWE Content Team
MITRE
2023-06-29
updated Mapping_Notes

CWE Content Team
MITRE
2025-09-09
4.18
2025-09-09
updated Common_Consequences, Description, Diagram, Other_Notes, References

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

Nick Johnston
2022-07-11
Identified incorrect language tag in demonstrative example.

Error Message Information Leaks
Error Message Information Leak
Information Exposure Through an Error Message