Exposure of Sensitive Information to an Unauthorized Actor

Draft Class
Structure: Simple
Description

The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.

Extended Description

There are many different kinds of mistakes that introduce information exposures. The severity of the error can range widely, depending on the context in which the product operates, the type of sensitive information that is revealed, and the benefits it may provide to an attacker. Some kinds of sensitive information include: - private, personal information, such as personal messages, financial data, health records, geographic location, or contact details - system status and environment, such as the operating system and installed packages - business secrets and intellectual property - network status and configuration - the product's own code or internal state - metadata, e.g. logging of connections or message headers - indirect information, such as a discrepancy between two internal operations that can be observed by an outsider Information might be sensitive to different parties, each of which may have their own expectations for whether the information should be protected. These parties include: - the product's own users - people or organizations whose information is created or used by the product, even if they are not direct product users - the product's administrators, including the admins of the system(s) and/or networks on which the product operates - the developer Information exposures can occur in different ways: - the code **explicitly inserts** sensitive information into resources or messages that are intentionally made accessible to unauthorized actors, but should not contain the information - i.e., the information should have been "scrubbed" or "sanitized" - a different weakness or mistake **indirectly inserts** the sensitive information into resources, such as a web script error revealing the full system path of the program. - the code manages resources that intentionally contain sensitive information, but the resources are **unintentionally made accessible** to unauthorized actors. In this case, the information exposure is resultant - i.e., a different weakness enabled the access to the information in the first place. It is common practice to describe any loss of confidentiality as an "information exposure," but this can lead to overuse of CWE-200 in CWE mapping. From the CWE perspective, loss of confidentiality is a technical impact that can arise from dozens of different weaknesses, such as insecure file permissions or out-of-bounds read. CWE-200 and its lower-level descendants are intended to cover the mistakes that occur in behaviors that explicitly manage, store, transfer, or cleanse sensitive information.

Common Consequences 1
Scope: Confidentiality

Impact: Read Application Data

Detection Methods 6
Automated Static Analysis - Binary or BytecodeSOAR Partial
According to SOAR [REF-1479], the following detection techniques may be useful: ``` Cost effective for partial coverage: ``` Bytecode Weakness Analysis - including disassembler + source code weakness analysis Inter-application Flow Analysis
Dynamic Analysis with Automated Results InterpretationHigh
According to SOAR [REF-1479], the following detection techniques may be useful: ``` Highly cost effective: ``` Web Application Scanner Web Services Scanner Database Scanners
Dynamic Analysis with Manual Results InterpretationSOAR Partial
According to SOAR [REF-1479], the following detection techniques may be useful: ``` Cost effective for partial coverage: ``` Fuzz Tester Framework-based Fuzzer Automated Monitored Execution Monitored Virtual Environment - run potentially malicious code in sandbox / wrapper / virtual machine, see if it does anything suspicious
Manual Static Analysis - Source CodeHigh
According to SOAR [REF-1479], the following detection techniques may be useful: ``` Highly cost effective: ``` Manual Source Code Review (not inspections)
Automated Static Analysis - Source CodeHigh
According to SOAR [REF-1479], the following detection techniques may be useful: ``` Highly cost effective: ``` Context-configured Source Code Weakness Analyzer ``` Cost effective for partial coverage: ``` Source code Weakness Analyzer
Architecture or Design ReviewHigh
According to SOAR [REF-1479], the following detection techniques may be useful: ``` Highly cost effective: ``` Formal Methods / Correct-By-Construction ``` Cost effective for partial coverage: ``` Attack Modeling Inspection (IEEE 1028 standard) (can apply to requirements, design, source code, etc.)
Potential Mitigations 1
Phase: Architecture and Design

Strategy: Separation of Privilege

Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
Demonstrative Examples 8

ID : DX-38

The following code checks validity of the supplied username and password and notifies the user of a successful or failed login.

Code Example:

Bad
Perl
perl
In the above code, there are different messages for when an incorrect username is supplied, versus when the username is correct but the password is wrong. This difference enables a potential attacker to understand the state of the login function, and could allow an attacker to discover a valid username by trying different values until the incorrect password message is returned. In essence, this makes it easier for an attacker to obtain half of the necessary authentication credentials.
While this type of information may be helpful to a user, it is also useful to a potential attacker. In the above example, the message for both failed cases should be the same, such as:

Code Example:

Result
bash

ID : DX-118

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

Code Example:

Bad
PHP
php

//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.

ID : DX-119

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.

Code Example:

Bad
Java
java
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 (Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')) to directly access the database.

ID : DX-120

This code stores location information about the current user:

Code Example:

Bad
Java
java

...*

java
When the application encounters an exception it will write the user object to the log. Because the user object contains location information, the user's location is also written to the log.

ID : DX-129

The following is an actual MySQL error statement:

Code Example:

Result
SQL
sql
The error clearly exposes the database credentials.

ID : DX-130

This code displays some information on a web page.

Code Example:

Bad
JSP
jsp
The code displays a user's credit card and social security numbers, even though they aren't absolutely necessary.

ID : DX-131

The following program changes its behavior based on a debug flag.

Code Example:

Bad
JSP
jsp
The code writes sensitive debug information to the client browser if the "debugEnabled" flag is set to true .

ID : DX-111

This code uses location to determine the user's current US State location.
First the application must declare that it requires the ACCESS_FINE_LOCATION permission in the application's manifest.xml:

Code Example:

Bad
XML
xml
During execution, a call to getLastLocation() will return a location based on the application's location permissions. In this case the application has permission for the most accurate location possible:

Code Example:

Bad
Java
java
While the application needs this information, it does not need to use the ACCESS_FINE_LOCATION permission, as the ACCESS_COARSE_LOCATION permission will be sufficient to identify which US state the user is in.
Observed Examples 19
CVE-2022-31162Rust library leaks Oauth client details in application debug logs
CVE-2021-25476Digital Rights Management (DRM) capability for mobile platform leaks pointer information, simplifying ASLR bypass
CVE-2001-1483Enumeration of valid usernames based on inconsistent responses
CVE-2001-1528Account number enumeration via inconsistent responses.
CVE-2004-2150User enumeration via discrepancies in error messages.
CVE-2005-1205Telnet protocol allows servers to obtain sensitive environment information from clients.
CVE-2002-1725Script calls phpinfo(), revealing system configuration to web user
CVE-2002-0515Product sets a different TTL when a port is being filtered than when it is not being filtered, which allows remote attackers to identify filtered ports by comparing TTLs.
CVE-2004-0778Version control system allows remote attackers to determine the existence of arbitrary files and directories via the -X command for an alternate history file, which causes different error messages to be returned.
CVE-2000-1117Virtual machine allows malicious web site operators to determine the existence of files on the client by measuring delays in the execution of the getSystemResource method.
CVE-2003-0190Product immediately sends an error message when a user does not exist, which allows remote attackers to determine valid usernames via a timing attack.
CVE-2008-2049POP3 server reveals a password in an error message after multiple APOP commands are sent. Might be resultant from another weakness.
CVE-2007-5172Program reveals password in error message if attacker can trigger certain database errors.
CVE-2008-4638Composite: application running with high privileges (Execution with Unnecessary Privileges) allows user to specify a restricted file to process, which generates a parsing error that leaks the contents of the file (Generation of Error Message Containing Sensitive Information).
CVE-2007-1409Direct request to library file in web application triggers pathname leak in error message.
CVE-2005-0603Malformed regexp syntax leads to information exposure in error message.
CVE-2004-2268Password exposed in debug information.
CVE-2003-1078FTP client with debug option enabled shows password to the screen.
CVE-2022-0708Collaboration platform does not clear team emails in a response, allowing leak of email addresses
References 3
Mobile App Top 10 List
Chris Wysopal
13-12-2010
ID: REF-172
Supplemental Details - 2022 CWE Top 25
MITRE
28-06-2022
ID: REF-1287
State-of-the-Art Resources (SOAR) for Software Vulnerability Detection, Test, and Evaluation
Gregory Larsen, E. Kenneth Hong Fong, David A. Wheeler, and Rama S. Moorthy
07-2014
ID: REF-1479
Likelihood of Exploit

High

Applicable Platforms
Languages:
Not Language-Specific : Undetermined
Technologies:
Mobile : Undetermined
Modes of Introduction
Architecture and Design
Implementation
Related Attack Patterns
Alternate Terms

Information Disclosure

This term is frequently used in vulnerability advisories to describe a consequence or technical impact, for any vulnerability that has a loss of confidentiality. Often, Exposure of Sensitive Information to an Unauthorized Actor can be misused to represent the loss of confidentiality, even when the mistake - i.e., the weakness - is not directly related to the mishandling of the information itself, such as an out-of-bounds read that accesses sensitive memory contents; here, the out-of-bounds read is the primary weakness, not the disclosure of the memory. In addition, this phrase is also used frequently in policies and legal documents, but it does not refer to any disclosure of security-relevant information.

Information Leak

This is a frequently used term, however the "leak" term has multiple uses within security. In some cases it deals with the accidental exposure of information from a different weakness, but in other cases (such as "memory leak"), this deals with improper tracking of resources, which can lead to exhaustion. As a result, CWE is actively avoiding usage of the "leak" term.
Taxonomy Mapping
  • PLOVER
  • OWASP Top Ten 2007
  • WASC
Notes
MaintenanceAs a result of mapping analysis in the 2020 Top 25 and more recent versions, this weakness is under review, since it is frequently misused in mapping to cover many problems that lead to loss of confidentiality. See Mapping Notes, Extended Description, and Alternate Terms.