Difference between revisions of "Setting Manipulation"

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[[Category:OWASP ASDR Project]]
  
==Abstract==
 
  
Allowing external control of system settings can disrupt service or cause an application to behave in unexpected ways.
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Last revision (mm/dd/yy): '''{{REVISIONMONTH}}/{{REVISIONDAY}}/{{REVISIONYEAR}}'''
  
 
==Description==
 
==Description==
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This attack aims to modify application settings in order to cause misleading data or advantages on the attacker's behalf. He may manipulate values in the system and manage specific user resources of the application or affect its functionalities.
  
Setting manipulation vulnerabilities occur when an attacker can control values that govern the behavior of the system, manage specific resources, or in some way affect the functionality of the application.
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An attacker can exploit several functionalities of the application using this attack technique, but it would not possible to describe all the ways of exploration, due to innumerable options that attacker may use to control the system values.  
  
Because setting manipulation covers a diverse set of functions, any attempt at illustrating it will inevitably be incomplete. Rather than searching for a tight-knit relationship between the functions addressed in the setting manipulation category, take a step back and consider the sorts of system values that an attacker should not be allowed to control.
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Using this attack technique, it is possible to manipulate settings by changing the application functions, such as calls to the database, blocking access to external libraries, and/or modification log files.
  
NOTE: The title was originally from [Fortify http://vulncat.fortifysoftware.com/] and was intended to be used for a vulnerability. We believe this title is more appropriate for an attack. The corresponding vulnerability is [[Allowing External Setting Manipulation]]
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== Risk Factors==
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TBD
  
==Examples ==
 
  
===Example1===
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==Example==
  
The following C# code reads a number from an HttpRequest and resizes a sorted list in preparation for copying the specified number of items into the list.
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===Example 1 ===
  
...
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An attacker needs to identify the variables without input validation or those improperly encapsulated to obtain success in the attack.
list.set_Capacity((int)Request.get_Item("numItems"));
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...
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The code in this example resizes a SortedList of items based on a value read from an HttpRequest. If an attacker provides a malicious value for numItems, the list may be truncated or extended beyond a reasonable size (potentially creating a low memory condition.)
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In general, do not allow user-provided or otherwise untrusted data to control sensitive values. The leverage that an attacker gains by controlling these values is not always immediately obvious, but do not underestimate the creativity of your attacker.
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The following example was based on those found in the Individual CWE Dictionary Definition (Setting Manipulation-15).  
  
===Example2===
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Consider the following piece of Java code:
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  …
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  conn.setCatalog(request.getParameter(“catalog”));
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  ...
  
An application takes a user-controllable parameter in the HTTP request to decide whether to turn on the debug mode.
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This fragment reads the string “catalog” from “HttpServletRequest” and sets it as the active catalog for a database connection. An attacker could manipulate this information and cause a connection error or unauthorized access to other catalogs.
  
==Example3==
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===Example 2 – Block Access to Libraries ===
  
The serialized object that stores the current system status can be overwritten by user input.  
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The attacker has the privileges to block application access to external libraries to execute this attack. It is necessary to discover what external libraries are accessed by the application and block them. The attacker needs to observe if the behavior of the system goes into an insecure/inconsistent state.
  
==Related Threats==
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In this case the application uses a third party cryptographic random number generation library to generate user Session IDs. An attacker may block access to this library by renaming it.
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Then the application will use the weak pseudo random number generation library. The attacker can use this weakness to predict the Session ID user; he/she attempts to perform elevation of privilege escalation and gains access to the user's account.
  
==Related Attacks==
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For more details about this attack, see:
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http://capec.mitre.org/data/definitions/96.html
  
==Related Vulnerabilities==
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==Related [[Threat Agents]]==
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* [[:Category: Logical Attacks]]
  
[[Allowing External Setting Manipulation]]
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==Related [[Attacks]]==
[[:Category:Input Validation Vulnerability]]
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* [[Denial of Service]]
  
==Related Countermeasures==
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==Related [[Vulnerabilities]]==
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* [[:Category:General Logic Error Vulnerability]]
  
[[:Category:Input Validation]]
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==Related [[Controls]]==
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* [[:Category: Error Handling]]
  
==Categories==
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==References==
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* http://cwe.mitre.org/data/definitions/15.html - Setting Manipulation
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* http://capec.mitre.org/data/definitions/13.html - Subverting Environment Variable Values
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* http://capec.mitre.org/data/definitions/96.html - Block Access to Libraries
  
[[Category:C]]
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[[Category:Code Snippet]]
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[[Category: Resource Manipulation]]
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[[Category: Attack]]

Latest revision as of 06:50, 23 April 2009

This is an Attack. To view all attacks, please see the Attack Category page.




Last revision (mm/dd/yy): 04/23/2009

Description

This attack aims to modify application settings in order to cause misleading data or advantages on the attacker's behalf. He may manipulate values in the system and manage specific user resources of the application or affect its functionalities.

An attacker can exploit several functionalities of the application using this attack technique, but it would not possible to describe all the ways of exploration, due to innumerable options that attacker may use to control the system values.

Using this attack technique, it is possible to manipulate settings by changing the application functions, such as calls to the database, blocking access to external libraries, and/or modification log files.

Risk Factors

TBD


Example

Example 1

An attacker needs to identify the variables without input validation or those improperly encapsulated to obtain success in the attack.

The following example was based on those found in the Individual CWE Dictionary Definition (Setting Manipulation-15).

Consider the following piece of Java code:

 …
 conn.setCatalog(request.getParameter(“catalog”));
 ...

This fragment reads the string “catalog” from “HttpServletRequest” and sets it as the active catalog for a database connection. An attacker could manipulate this information and cause a connection error or unauthorized access to other catalogs.

Example 2 – Block Access to Libraries

The attacker has the privileges to block application access to external libraries to execute this attack. It is necessary to discover what external libraries are accessed by the application and block them. The attacker needs to observe if the behavior of the system goes into an insecure/inconsistent state.

In this case the application uses a third party cryptographic random number generation library to generate user Session IDs. An attacker may block access to this library by renaming it. Then the application will use the weak pseudo random number generation library. The attacker can use this weakness to predict the Session ID user; he/she attempts to perform elevation of privilege escalation and gains access to the user's account.

For more details about this attack, see: http://capec.mitre.org/data/definitions/96.html

Related Threat Agents

Related Attacks

Related Vulnerabilities

Related Controls

References