An information exposure is the intentional or unintentional disclosure of information to an actor that is not explicitly authorized to have access to that information.
Extended Description
The information either:
is regarded as sensitive within the product's own functionality, such as a private message; or
provides information about the product or its environment that could be useful in an attack but is normally not available to the attacker, such as the installation path of a product that is remotely accessible.
Many information exposures are resultant (e.g. PHP script error revealing the full path of the program), but they can also be primary (e.g. timing discrepancies in cryptography). There are many different types of problems that involve information exposures. Their severity can range widely depending on the type of information that is revealed.
Alternate Terms
Information Leak:
This is a frequently used term, however the "leak" term has multiple uses within security. In some cases it deals with exposure of information, 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.
Information Disclosure:
This term is frequently used in vulnerability databases and other sources, however "disclosure" does not always have security implications. The phrase "information disclosure" is also used frequently in policies and legal documents, but do not refer to disclosure of security-relevant information.
Relationships
The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.
Relevant to the view "Research Concepts" (CWE-1000)
Nature
Type
ID
Name
ChildOf
Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More general than a Base weakness.
Variant - a weakness that is described at a very low level of detail, typically limited to a specific language or technology. More specific than a Base weakness.
Base - a weakness that is described in an abstract fashion, but with sufficient details to infer specific methods for detection and prevention. More general than a Variant weakness, but more specific than a Class weakness.
Base - a weakness that is described in an abstract fashion, but with sufficient details to infer specific methods for detection and prevention. More general than a Variant weakness, but more specific than a Class weakness.
Base - a weakness that is described in an abstract fashion, but with sufficient details to infer specific methods for detection and prevention. More general than a Variant weakness, but more specific than a Class weakness.
Base - a weakness that is described in an abstract fashion, but with sufficient details to infer specific methods for detection and prevention. More general than a Variant weakness, but more specific than a Class weakness.
Variant - a weakness that is described at a very low level of detail, typically limited to a specific language or technology. More specific than a Base weakness.
Variant - a weakness that is described at a very low level of detail, typically limited to a specific language or technology. More specific than a Base weakness.
Base - a weakness that is described in an abstract fashion, but with sufficient details to infer specific methods for detection and prevention. More general than a Variant weakness, but more specific than a Class weakness.
Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More general than a Base weakness.
Variant - a weakness that is described at a very low level of detail, typically limited to a specific language or technology. More specific than a Base weakness.
Variant - a weakness that is described at a very low level of detail, typically limited to a specific language or technology. More specific than a Base weakness.
Variant - a weakness that is described at a very low level of detail, typically limited to a specific language or technology. More specific than a Base weakness.
Base - a weakness that is described in an abstract fashion, but with sufficient details to infer specific methods for detection and prevention. More general than a Variant weakness, but more specific than a Class weakness.
Variant - a weakness that is described at a very low level of detail, typically limited to a specific language or technology. More specific than a Base weakness.
Variant - a weakness that is described at a very low level of detail, typically limited to a specific language or technology. More specific than a Base weakness.
Variant - a weakness that is described at a very low level of detail, typically limited to a specific language or technology. More specific than a Base weakness.
Variant - a weakness that is described at a very low level of detail, typically limited to a specific language or technology. More specific than a Base weakness.
Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)
Nature
Type
ID
Name
ParentOf
Base - a weakness that is described in an abstract fashion, but with sufficient details to infer specific methods for detection and prevention. More general than a Variant weakness, but more specific than a Class weakness.
Base - a weakness that is described in an abstract fashion, but with sufficient details to infer specific methods for detection and prevention. More general than a Variant weakness, but more specific than a Class weakness.
Variant - a weakness that is described at a very low level of detail, typically limited to a specific language or technology. More specific than a Base weakness.
Variant - a weakness that is described at a very low level of detail, typically limited to a specific language or technology. More specific than a Base weakness.
Variant - a weakness that is described at a very low level of detail, typically limited to a specific language or technology. More specific than a Base weakness.
Base - a weakness that is described in an abstract fashion, but with sufficient details to infer specific methods for detection and prevention. More general than a Variant weakness, but more specific than a Class weakness.
Base - a weakness that is described in an abstract fashion, but with sufficient details to infer specific methods for detection and prevention. More general than a Variant weakness, but more specific than a Class weakness.
Base - a weakness that is described in an abstract fashion, but with sufficient details to infer specific methods for detection and prevention. More general than a Variant weakness, but more specific than a Class weakness.
Base - a weakness that is described in an abstract fashion, but with sufficient details to infer specific methods for detection and prevention. More general than a Variant weakness, but more specific than a Class weakness.
Variant - a weakness that is described at a very low level of detail, typically limited to a specific language or technology. More specific than a Base weakness.
Variant - a weakness that is described at a very low level of detail, typically limited to a specific language or technology. More specific than a Base weakness.
Base - a weakness that is described in an abstract fashion, but with sufficient details to infer specific methods for detection and prevention. More general than a Variant weakness, but more specific than a Class weakness.
Variant - a weakness that is described at a very low level of detail, typically limited to a specific language or technology. More specific than a Base weakness.
Variant - a weakness that is described at a very low level of detail, typically limited to a specific language or technology. More specific than a Base weakness.
Variant - a weakness that is described at a very low level of detail, typically limited to a specific language or technology. More specific than a Base weakness.
Base - a weakness that is described in an abstract fashion, but with sufficient details to infer specific methods for detection and prevention. More general than a Variant weakness, but more specific than a Class weakness.
Variant - a weakness that is described at a very low level of detail, typically limited to a specific language or technology. More specific than a Base weakness.
Variant - a weakness that is described at a very low level of detail, typically limited to a specific language or technology. More specific than a Base weakness.
Variant - a weakness that is described at a very low level of detail, typically limited to a specific language or technology. More specific than a Base weakness.
Variant - a weakness that is described at a very low level of detail, typically limited to a specific language or technology. More specific than a Base weakness.
The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.
Phase
Note
Architecture and Design
Implementation
Applicable Platforms
The listings below show possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.
The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.
Scope
Impact
Likelihood
Confidentiality
Technical Impact: Read Application Data
Likelihood Of Exploit
High
Demonstrative Examples
Example 1
The following code checks validity of the supplied username and password and notifies the user of a successful or failed login.
(bad code)
Example Language: Perl
my $username=param('username'); my $password=param('password');
if (IsValidUsername($username) == 1) {
if (IsValidPassword($username, $password) == 1) {
print "Login Successful";
} else {
print "Login Failed - incorrect password";
}
} else {
print "Login Failed - unknown username";
}
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:
(result)
"Login Failed - incorrect username or password"
Example 2
This code tries to open a database connection, and prints any exceptions that occur.
(bad code)
Example Language: Java
try {
openDbConnection();
} //print exception message that includes exception message and configuration file location catch (Exception $e) {
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.
Example 3
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.
(bad code)
Example Language: Java
public BankAccount getUserBankAccount(String username, String accountNumber) {
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.
Example 4
This code stores location information about the current user:
(bad code)
Example Language: Java
locationClient = new LocationClient(this, this, this); locationClient.connect(); currentUser.setLocation(locationClient.getLastLocation()); ...
catch (Exception e) {
AlertDialog.Builder builder = new AlertDialog.Builder(this); builder.setMessage("Sorry, this application has experienced an error."); AlertDialog alert = builder.create(); alert.show(); Log.e("ExampleActivity", "Caught exception: " + e + " While on User:" + User.toString());
}
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.
Product 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.
Version 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.
Virtual 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.
Malformed regexp syntax leads to information exposure in error message.
Potential Mitigations
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 that the compartmentalization serves to allow for and further reinforce privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide when it is appropriate to use and to drop system privileges.
Weakness Ordinalities
Ordinality
Description
Resultant
(where the weakness is typically related to the presence of some other weaknesses)
Detection Methods
Automated Static Analysis - Binary or Bytecode
According to SOAR, the following detection techniques may be useful:
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
Nature
Type
ID
Name
MemberOf
View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).
View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).
View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).
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Page Last Updated:
September 19, 2019
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Description
Relevant to the view "Research Concepts" (CWE-1000)
