Description

The software does not perform an authorization check when an actor attempts to access a resource or perform an action.

An access control list (ACL) represents who/what has permissions to a given object. Different operating systems implement (ACLs) in different ways. In UNIX, there are three types of permissions: read, write, and execute. Users are divided into three classes for file access: owner, group owner, and all other users where each class has a separate set of rights. In Windows NT, there are four basic types of permissions for files: “No access”, “Read access”, “Change access”, and “Full control”. Windows NT extends the concept of three types of users in UNIX to include a list of users and groups along with their associated permissions. A user can create an object (file) and assign specified permissions to that object.

Modes of Introduction:

– Architecture and Design

Likelihood of Exploit: High

 

Related Weaknesses

CWE-285
CWE-284

 

Consequences

Confidentiality: Read Application Data, Read Files or Directories

An attacker could read sensitive data, either by reading the data directly from a data store that is not restricted, or by accessing insufficiently-protected, privileged functionality to read the data.

Integrity: Modify Application Data, Modify Files or Directories

An attacker could modify sensitive data, either by writing the data directly to a data store that is not restricted, or by accessing insufficiently-protected, privileged functionality to write the data.

Access Control: Gain Privileges or Assume Identity, Bypass Protection Mechanism

An attacker could gain privileges by modifying or reading critical data directly, or by accessing privileged functionality.

 

Potential Mitigations

Phase: Architecture and Design

Effectiveness:

Description: 

Phase: Architecture and Design

Effectiveness:

Description: 

Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient’s doctor [REF-7].

Phase: Architecture and Design

Effectiveness:

Description: 

Phase: Architecture and Design

Effectiveness:

Description: 

Phase: System Configuration, Installation

Effectiveness:

Description: 

Use the access control capabilities of your operating system and server environment and define your access control lists accordingly. Use a “default deny” policy when defining these ACLs.

CVE References

 

• CVE-2009-3168
  • Web application does not restrict access to admin scripts, allowing authenticated users to reset administrative passwords.

• CVE-2009-3597
  • Web application stores database file under the web root with insufficient access control (CWE-219), allowing direct request.

• CVE-2009-2282
  • Terminal server does not check authorization for guest access.

• CVE-2008-5027
  • System monitoring software allows users to bypass authorization by creating custom forms.

• CVE-2009-3781
  • Content management system does not check access permissions for private files, allowing others to view those files.

• CVE-2008-6548
  • Product does not check the ACL of a page accessed using an “include” directive, allowing attackers to read unauthorized files.

• CVE-2009-2960
  • Web application does not restrict access to admin scripts, allowing authenticated users to modify passwords of other users.

• CVE-2009-3230
  • Database server does not use appropriate privileges for certain sensitive operations.

• CVE-2009-2213
  • Gateway uses default “Allow” configuration for its authorization settings.

• CVE-2009-0034
  • Chain: product does not properly interpret a configuration option for a system group, allowing users to gain privileges.

• CVE-2008-6123
  • Chain: SNMP product does not properly parse a configuration option for which hosts are allowed to connect, allowing unauthorized IP addresses to connect.

• CVE-2008-7109
  • Chain: reliance on client-side security (CWE-602) allows attackers to bypass authorization using a custom client.

• CVE-2008-3424
  • Chain: product does not properly handle wildcards in an authorization policy list, allowing unintended access.

• CVE-2005-1036
  • Chain: Bypass of access restrictions due to improper authorization (CWE-862) of a user results from an improperly initialized (CWE-909) I/O permission bitmap

• CVE-2008-4577
  • ACL-based protection mechanism treats negative access rights as if they are positive, allowing bypass of intended restrictions.

• CVE-2007-2925
  • Default ACL list for a DNS server does not set certain ACLs, allowing unauthorized DNS queries.

• CVE-2006-6679
  • Product relies on the X-Forwarded-For HTTP header for authorization, allowing unintended access by spoofing the header.

• CVE-2005-3623
  • OS kernel does not check for a certain privilege before setting ACLs for files.

• CVE-2005-2801
  • Chain: file-system code performs an incorrect comparison (CWE-697), preventing default ACLs from being properly applied.

• CVE-2001-1155
  • Chain: product does not properly check the result of a reverse DNS lookup because of operator precedence (CWE-783), allowing bypass of DNS-based access restrictions.

• CVE-2020-17533
  • Chain: unchecked return value (CWE-252) of some functions for policy enforcement leads to authorization bypass (CWE-862)