CWE Reference

CWE-209: Generation of Error Message Containing Sensitive Information

Official CWE-209 CWE context with Glexia analysis, remediation guidance, related CVEs, and ATT&CK context.

Release 4.20weaknessDraft

Glexia's Take

CWE-209: Generation of Error Message Containing Sensitive Information

Generation of Error Message Containing Sensitive Information represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Executive Impact

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.

Developer Pattern

CWE-209 is the kind of defect developers can usually prevent with explicit validation, safer framework defaults, and tests that exercise hostile input or unsafe state transitions.

Confidence

high confidence from CWE-209, 4.20.

Official CWE Definition

CWE-209: Generation of Error Message Containing Sensitive Information

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

Type: weakness
Abstraction: Base
Status: Draft
Source: MITRE CWE definition

Developer And Remediation Guidance

How teams prevent and detect this weakness

Causes

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

Remediation

Implementation: [object Object]
Implementation: Handle exceptions internally and do not display errors containing potentially sensitive information to a user.
Implementation: 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.
Implementation,Build and Compilation: 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.

Detection

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.
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.
Automated Dynamic Analysis: [object Object]
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.)

Mappings

Related CVEs, CWEs, and ATT&CK context

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ATT&CK Relevance

ATT&CK relevance is shown only when reviewed or responsibly inferred.