CWE

Incorrect Use of Privileged APIs

ID: 648		Date: (C)2012-05-14   (M)2022-10-10
Type: weakness		Status: INCOMPLETE
Abstraction Type: Base

Description

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 are 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 do not 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.

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.

Likelihood of Exploit: Low

Applicable Platforms
Language Class: All

Time Of Introduction

• Architecture and Design
• Implementation
• Operation

Related Attack Patterns

• CAPEC-107
• CAPEC-234

Common Consequences

Scope	Technical Impact	Notes
Access_Control	Gain privileges / assume identity	An attacker may be able to elevate privileges.
Confidentiality	Read application data	An attacker may be able to obtain sensitive information.
Integrity Confidentiality Availability	Execute unauthorized code or commands	An attacker may be able to execute code.

Detection Methods
None

Potential Mitigations

Phase	Strategy	Description	Effectiveness	Notes
Implementation		Before calling privileged APIs, always ensure that the assumptions made by the privileged code hold true prior to making the call.
Architecture and Design		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.
Implementation		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.
Implementation		If privileged APIs do not 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.
Implementation		Only call privileged APIs from safe, consistent and expected state.
Implementation		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

Related CWE	Type	View	Chain
CWE-648 ChildOf CWE-907	Category	CWE-888

Demonstrative Examples
None

Observed Examples

1. : From http://xforce.iss.net/xforce/xfdb/12848: 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.

For more examples, refer to CVE relations in the bottom box.

White Box Definitions
None

Black Box Definitions
None

Taxynomy Mappings
None

References:
None