StandardSeverity: HighCAPEC-1

CAPEC-1: Accessing Functionality Not Properly Constrained by ACLs

Description

In applications, particularly web applications, access to functionality is mitigated by an authorization framework. This framework maps Access Control Lists (ACLs) to elements of the application's functionality; particularly URL's for web apps. In the case that the administrator failed to specify an ACL for a particular element, an attacker may be able to access it with impunity. An attacker with the ability to access functionality not properly constrained by ACLs can obtain sensitive information and possibly compromise the entire application. Such an attacker can access resources that must be available only to users at a higher privilege level, can access management sections of the application, or can run queries for data that they otherwise not supposed to.

Likelihood of attack: High
Typical severity: High
Abstraction: StandardA specific methodology or technique used in an attack.

Mechanism of attack: Subvert Access Control

Prerequisites

The application must be navigable in a manner that associates elements (subsections) of the application with ACLs.
The various resources, or individual URLs, must be somehow discoverable by the attacker
The administrator must have forgotten to associate an ACL or has associated an inappropriately permissive ACL with a particular navigable resource.

Skills required

LowIn order to discover unrestricted resources, the attacker does not need special tools or skills. They only have to observe the resources or access mechanisms invoked as each action is performed and then try and access those access mechanisms directly.

Consequences

ConfidentialityAccess ControlAuthorization
Gain Privileges

Mitigations

In a J2EE setting, administrators can associate a role that is impossible for the authenticator to grant users, such as NoAccess, with all Servlets to which access is guarded by a limited number of servlets visible to, and accessible by, the user. Having done so, any direct access to those protected Servlets will be prohibited by the web container. In a more general setting, the administrator must mark every resource besides the ones supposed to be exposed to the user as accessible by a role impossible for the user to assume. The default security setting must be to deny access and then grant...

Related weaknesses (CWE)

ATT&CK techniques (CAPEC taxonomy mapping)

T1574.010Hijack Execution Flow: Services File Permissions Weakness

Across MITRE's defensive frameworks

Linked through the 1 ATT&CK technique above.

Counter with D3FEND

Defensive techniques MITRE D3FEND maps to the same ATT&CK techniques.

12 more in the full list

Detect with CAR

MITRE CAR analytics that cover the same ATT&CK techniques.

Related attack patterns

Parent

CAPEC-122Privilege AbuseMeta

More specific patterns