Home > CAPEC List > CAPEC-96: Block Access to Libraries (Version 2.4)  

CAPEC-96: Block Access to Libraries

 
Block Access to Libraries
Definition in a New Window Definition in a New Window
Attack Pattern ID: 96
Abstraction: Standard
Status: Draft
Completeness: Complete
+ Description

Summary

An application typically makes calls to functions that are a part of libraries external to the application. These libraries may be part of the operating system or they may be third party libraries. It is possible that the application does not handle situations properly where access to these libraries has been blocked. Depending on the error handling within the application, blocked access to libraries may leave the system in an insecure state that could be leveraged by an attacker.

Attack Execution Flow

Explore
  1. Determine what external libraries the application accesses.

Experiment
  1. Block access to the external libraries accessed by the application.

  2. Monitor the behavior of the system to see if it goes into an insecure/inconsistent state.

  3. If the system does go into an insecure/inconsistent state, leverage that to obtain information about the system functionality or data, elevate access control, etc. The rest of this attack will depend on the context and the desired goal.

+ Attack Prerequisites
  • An application requires access to external libraries.

  • An attacker has the privileges to block application access to external libraries.

+ Typical Severity

Medium

+ Typical Likelihood of Exploit

Likelihood: Medium

+ Methods of Attack
  • API Abuse
  • Modification of Resources
+ Examples-Instances

Description

A web-based system uses a third party cryptographic random number generation library that derives entropy from machine's hardware. This library is used in generation of user session ids used by the application. If the library is inaccessible, the application instead uses a software based weak pseudo random number generation library. An attacker of the system blocks access of the application to the third party cryptographic random number generation library (by renaming it). The application in turn uses the weak pseudo random number generation library to generate session ids that are predictable. An attacker then leverages this weakness to guess a session id of another user to perform a horizontal elevation of privilege escalation and gain access to another user's account.

+ Attacker Skills or Knowledge Required

Skill or Knowledge Level: Low

+ Solutions and Mitigations

Ensure that application handles situations where access to APIs in external libraries is not available securely. If the application cannot continue its execution safely it should fail in a consistent and secure fashion.

+ Attack Motivation-Consequences
ScopeTechnical ImpactNote
Availability
Alter execution logic
Confidentiality
"Varies by context"
Confidentiality
Access_Control
Authorization
Bypass protection mechanism
+ Purposes
  • Exploitation
+ CIA Impact
Confidentiality Impact: LowIntegrity Impact: LowAvailability Impact: High
+ Technical Context
Architectural Paradigms
All
Frameworks
All
Platforms
All
Languages
All
+ Content History
Submissions
SubmitterOrganizationDateComments
Sean BarnumCigital, Inc.2007-03-25Identified priority for pattern creation
Modifications
ModifierOrganizationDateCommentsSource
Evgeny LebanidzeCigital, Inc.,2007-03-21Fleshed out content for pattern
Sean BarnumCigital, Inc2007-04-16Review and revise
CAPEC Content TeamThe MITRE Corporation2014-02-06Updated Attack_Phases, Attack_Prerequisites, Examples-InstancesInternal

Page Last Updated: April 10, 2014