Exposure of System Data to an Unauthorized Control Sphere
Weakness ID: 497 (Weakness Variant)Status: Incomplete
+ Description

Description Summary

Exposing system data or debugging information helps an adversary learn about the system and form an attack plan.

Extended Description

An information exposure occurs when system data or debugging information leaves the program through an output stream or logging function that makes it accessible to unauthorized parties. An attacker can also cause errors to occur by submitting unusual requests to the web application. The response to these errors can reveal detailed system information, deny service, cause security mechanisms to fail, and crash the server. An attacker can use error messages that reveal technologies, operating systems, and product versions to tune the attack against known vulnerabilities in these technologies. An application may use diagnostic methods that provide significant implementation details such as stack traces as part of its error handling mechanism.

+ Time of Introduction
  • Implementation
+ Applicable Platforms

Languages

All

+ Demonstrative Examples

Example 1

The following code prints the path environment variable to the standard error stream:

(Bad Code)
Example Language: C 
char* path = getenv("PATH");
...
sprintf(stderr, "cannot find exe on path %s\n", path);

Example 2

The following code prints an exception to the standard error stream:

(Bad Code)
Example Language: Java 
try {
...
} catch (Exception e) {
e.printStackTrace();
}
(Bad Code)
 
try {
...
} catch (Exception e) {
Console.Writeline(e);
}

Depending upon the system configuration, this information can be dumped to a console, written to a log file, or exposed to a remote user. In some cases the error message tells the attacker precisely what sort of an attack the system will be vulnerable to. For example, a database error message can reveal that the application is vulnerable to a SQL injection attack. Other error messages can reveal more oblique clues about the system. In the example above, the search path could imply information about the type of operating system, the applications installed on the system, and the amount of care that the administrators have put into configuring the program.

Example 3

The following code constructs a database connection string, uses it to create a new connection to the database, and prints it to the console.

(Bad Code)
Example Language: C# 
string cs="database=northwind; server=mySQLServer...";
SqlConnection conn=new SqlConnection(cs);
...
Console.Writeline(cs);

Depending on the system configuration, this information can be dumped to a console, written to a log file, or exposed to a remote user. In some cases the error message tells the attacker precisely what sort of an attack the system is vulnerable to. For example, a database error message can reveal that the application is vulnerable to a SQL injection attack. Other error messages can reveal more oblique clues about the system. In the example above, the search path could imply information about the type of operating system, the applications installed on the system, and the amount of care that the administrators have put into configuring the program.

+ Potential Mitigations

Production applications should never use methods that generate internal details such as stack traces and error messages unless that information is directly committed to a log that is not viewable by the end user. All error message text should be HTML entity encoded before being written to the log file to protect against potential cross-site scripting attacks against the viewer of the logs

+ Relationships
NatureTypeIDNameView(s) this relationship pertains toView(s)
ChildOfWeakness ClassWeakness Class200Information Exposure
Development Concepts (primary)699
Research Concepts (primary)1000
ChildOfWeakness ClassWeakness Class485Insufficient Encapsulation
Seven Pernicious Kingdoms (primary)700
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
7 Pernicious KingdomsSystem Information Leak
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
7 Pernicious KingdomsExternally Mined
Modifications
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigitalExternal
updated Time of Introduction
2008-09-08CWE Content TeamMITREInternal
updated Relationships, Other Notes, Taxonomy Mappings, Type
2009-03-10CWE Content TeamMITREInternal
updated Demonstrative Examples
2009-05-27CWE Content TeamMITREInternal
updated Demonstrative Examples
2009-07-27CWE Content TeamMITREInternal
updated Demonstrative Examples
2009-10-29CWE Content TeamMITREInternal
updated Description, Other Notes
2009-12-28CWE Content TeamMITREInternal
updated Description, Name
Previous Entry Names
Change DatePrevious Entry Name
2008-04-11System Information Leak
2009-12-28Information Leak of System Data
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