CAPEC-96
Block Access to Libraries
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.
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Explain the attack pattern CAPEC-96: Block Access to Libraries: how it unfolds, what it needs and how to prevent and detect it in my systems. Use https://capec.mitre.org/data/definitions/96.html and https://cve.bz/cve/capec/96?via=ask-ai-copy, which lists recent CVEs with the weaknesses it exploits. Cite the sources.Opens a third-party assistant; its answer is its own, not cve.bz's. The prompt holds only this attack pattern's id and public links.
How the attack unfolds
Explore
The attacker looks for a way in.
Determine what external libraries the application accesses.
Experiment
They probe what they found.
Block access to the external libraries accessed by the application.
Monitor the behavior of the system to see if it goes into an insecure/inconsistent state.
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.
Prerequisites
An application requires access to external libraries.
An attacker has the privileges to block application access to external libraries.
Skills required
- Low skill
Knowledge of how to block access to libraries, as well as knowledge of how to leverage the resulting state of the application based on the failed call.
Consequences
| Impact | Affects | Note |
|---|---|---|
| Alter Execution Logic | Availability | |
| Other | Confidentiality | |
| Bypass Protection Mechanism | Confidentiality, Access Control, Authorization |
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.
Weaknesses it exploits
- CWE-589 Call to Non-ubiquitous API
Related attack patterns
- Part of
- CAPEC-603 Blockage
Examples
A web-based system uses a third party cryptographic random number generation library that derives entropy fro…
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.
MITRE's words, unchanged: CAPEC-96 at MITRE. CAPEC is Copyright © 2007–2026, The MITRE Corporation, used under the CAPEC terms of use: “The MITRE Corporation (MITRE) hereby grants you a non-exclusive, royalty-free license to use Common Attack Pattern Enumeration and Classification (CAPEC™) for research, development, and commercial purposes. Any copy you make for such purposes is authorized provided that you reproduce MITRE’s copyright designation and this license in any such copy.” CAPEC and the CAPEC logo are trademarks of The MITRE Corporation. Credits. All attack patterns.