Incorrect Use of Privileged APIs
Weakness ID: 648 (Weakness Base)Status: Incomplete
+ Description

Description Summary

The application does not conform to the API requirements for a function call that requires extra privileges. This could allow attackers to gain privileges by causing the function to be called incorrectly.

Extended Description

When an application contains certain functions that perform operations requiring an elevated level of privilege, the caller of a privileged API must be careful to:

- ensure that assumptions made by the APIs is valid, such as validity of arguments

- account for known weaknesses in the design/implementation of the API

- call the API from a safe context

If the caller of the API does not follow these requirements, then it may allow a malicious user or process to elevate their privilege, hijack the process, or steal sensitive data.

For instance, it is important to know if privileged APIs fail to properly shed their privileges before returning to the caller or if the privileged function might make certain assumptions about the data, context or state information passed to it by the caller. It is important to always know when and how privileged APIs can be called in order to ensure that their elevated level of privilege cannot be exploited.

+ Time of Introduction
  • Architecture and Design
  • Implementation
  • Operation
+ Applicable Platforms



+ Common Consequences
Access Control

Elevation of privilege


Information disclosure


Arbitrary code execution

+ Likelihood of Exploit


+ Enabling Factors for Exploitation

An application contains functions running processes that hold higher privileges.

There is code in the application that calls the privileged APIs.

There is a way for a user to control the data that is being passed to the privileged API or control the context from which it is being called.

+ Observed Examples
From man-db is a Unix utility that displays online help files. man-db versions 2.3.12 beta and 2.3.18 to 2.4.1 could allow a local attacker to gain privileges, caused by a vulnerability when the open cat stream function is called. If man-db is installed setuid, a local attacker could exploit this vulnerability to gain "man" user privileges.
+ Potential Mitigations

Phase: Implementation

Before calling privileged APIs, always ensure that the assumptions made by the privileged code hold true prior to making the call.

Know architecture and implementation weaknesses of the privileged APIs and make sure to account for these weaknesses before calling the privileged APIs to ensure that they can be called safely.

If privileged APIs make certain assumptions about data, context or state validity that are passed by the caller, the calling code must ensure that these assumptions have been validated prior to making the call.

If privileged APIs fail to shed their privilege prior to returning to the calling code, then calling code needs to shed these privileges immediately and safely right after the call to the privileged APIs. In particular, the calling code needs to ensure that a privileged thread of execution will never be returned to the user or made available to user-controlled processes.

Only call privileged APIs from safe, consistent and expected state.

Ensure that a failure or an error will not leave a system in a state where privileges are not properly shed and privilege escalation is possible (i.e. fail securely with regards to handling of privileges).

+ Relationships
NatureTypeIDNameView(s) this relationship pertains toView(s)
ChildOfWeakness ClassWeakness Class227Failure to Fulfill API Contract ('API Abuse')
Research Concepts1000
ChildOfCategoryCategory265Privilege / Sandbox Issues
Development Concepts (primary)699
ChildOfWeakness BaseWeakness Base269Improper Privilege Management
Research Concepts (primary)1000
+ Related Attack Patterns
CAPEC-IDAttack Pattern Name
(CAPEC Version: 1.4)
107Cross Site Tracing
+ Content History
Submission DateSubmitterOrganizationSource
2008-01-30Evgeny LebanidzeCigitalExternal Submission
Modification DateModifierOrganizationSource
2008-09-08CWE Content TeamMITREInternal
updated Common Consequences, Relationships
2008-10-14CWE Content TeamMITREInternal
updated Description, Potential Mitigations
2009-05-27CWE Content TeamMITREInternal
updated Name, Related Attack Patterns
2009-10-29CWE Content TeamMITREInternal
updated Common Consequences
Previous Entry Names
Change DatePrevious Entry Name
2009-05-27Improper Use of Privileged APIs