Assuming a user with a given identity, authorization is the process of determining whether that user can access a given resource, based on the user's privileges and any permissions or other access-control specifications that apply to the resource.
When access control checks are not applied consistently - or not at all - users are able to access data or perform actions that they should not be allowed to perform. This can lead to a wide range of problems, including information exposures, denial of service, and arbitrary code execution.
REALIZATION: This weakness is caused during implementation of an architectural security tactic.
A developer may introduce authorization weaknesses because of a lack of understanding about the underlying technologies. For example, a developer may assume that attackers cannot modify certain inputs such as headers or cookies.
Authorization weaknesses may arise when a single-user application is ported to a multi-user environment.
Scope | Impact | Likelihood |
---|---|---|
Confidentiality | Read Application Data, Read Files or Directories Note: An attacker could read sensitive data, either by reading the data directly from a data store that is not properly restricted, or by accessing insufficiently-protected, privileged functionality to read the data. | |
Integrity | Modify Application Data, Modify Files or Directories Note: An attacker could modify sensitive data, either by writing the data directly to a data store that is not properly restricted, or by accessing insufficiently-protected, privileged functionality to write the data. | |
Access Control | Gain Privileges or Assume Identity Note: An attacker could gain privileges by modifying or reading critical data directly, or by accessing insufficiently-protected, privileged functionality. |
Reference | Description |
---|---|
Go-based continuous deployment product does not check that a user has certain privileges to update or create an app, allowing adversaries to read sensitive repository information | |
Web application does not restrict access to admin scripts, allowing authenticated users to reset administrative passwords. | |
Web application does not restrict access to admin scripts, allowing authenticated users to modify passwords of other users. | |
Web application stores database file under the web root with insufficient access control (CWE-219), allowing direct request. | |
Terminal server does not check authorization for guest access. | |
Database server does not use appropriate privileges for certain sensitive operations. | |
Gateway uses default "Allow" configuration for its authorization settings. | |
Chain: product does not properly interpret a configuration option for a system group, allowing users to gain privileges. | |
Chain: SNMP product does not properly parse a configuration option for which hosts are allowed to connect, allowing unauthorized IP addresses to connect. | |
System monitoring software allows users to bypass authorization by creating custom forms. | |
Chain: reliance on client-side security (CWE-602) allows attackers to bypass authorization using a custom client. | |
Chain: product does not properly handle wildcards in an authorization policy list, allowing unintended access. | |
Content management system does not check access permissions for private files, allowing others to view those files. | |
ACL-based protection mechanism treats negative access rights as if they are positive, allowing bypass of intended restrictions. | |
Product does not check the ACL of a page accessed using an "include" directive, allowing attackers to read unauthorized files. | |
Default ACL list for a DNS server does not set certain ACLs, allowing unauthorized DNS queries. | |
Product relies on the X-Forwarded-For HTTP header for authorization, allowing unintended access by spoofing the header. | |
OS kernel does not check for a certain privilege before setting ACLs for files. | |
Chain: file-system code performs an incorrect comparison (CWE-697), preventing default ACLs from being properly applied. | |
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. |
Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries.
Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
For example, consider using authorization frameworks such as the JAAS Authorization Framework [REF-233] and the OWASP ESAPI Access Control feature [REF-45].
For web applications, make sure that the access control mechanism is enforced correctly at the server side on every page. Users should not be able to access any unauthorized functionality or information by simply requesting direct access to that page.
One way to do this is to ensure that all pages containing sensitive information are not cached, and that all such pages restrict access to requests that are accompanied by an active and authenticated session token associated with a user who has the required permissions to access that page.
Automated static analysis is useful for detecting commonly-used idioms for authorization. A tool may be able to analyze related configuration files, such as .htaccess in Apache web servers, or detect the usage of commonly-used authorization libraries.
Generally, automated static analysis tools have difficulty detecting custom authorization schemes. In addition, the software's design may include some functionality that is accessible to any user and does not require an authorization check; an automated technique that detects the absence of authorization may report false positives.
This weakness can be detected using tools and techniques that require manual (human) analysis, such as penetration testing, threat modeling, and interactive tools that allow the tester to record and modify an active session.
Specifically, manual static analysis is useful for evaluating the correctness of custom authorization mechanisms.
According to SOAR, the following detection techniques may be useful:
According to SOAR, the following detection techniques may be useful:
According to SOAR, the following detection techniques may be useful:
According to SOAR, the following detection techniques may be useful:
According to SOAR, the following detection techniques may be useful:
According to SOAR, the following detection techniques may be useful:
CAPEC-ID | Attack Pattern Name |
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CAPEC-1 | Accessing Functionality Not Properly Constrained by ACLs 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. |
CAPEC-104 | Cross Zone Scripting An attacker is able to cause a victim to load content into their web-browser that bypasses security zone controls and gain access to increased privileges to execute scripting code or other web objects such as unsigned ActiveX controls or applets. This is a privilege elevation attack targeted at zone-based web-browser security. |
CAPEC-127 | Directory Indexing An adversary crafts a request to a target that results in the target listing/indexing the content of a directory as output. One common method of triggering directory contents as output is to construct a request containing a path that terminates in a directory name rather than a file name since many applications are configured to provide a list of the directory's contents when such a request is received. An adversary can use this to explore the directory tree on a target as well as learn the names of files. This can often end up revealing test files, backup files, temporary files, hidden files, configuration files, user accounts, script contents, as well as naming conventions, all of which can be used by an attacker to mount additional attacks. |
CAPEC-13 | Subverting Environment Variable Values The adversary directly or indirectly modifies environment variables used by or controlling the target software. The adversary's goal is to cause the target software to deviate from its expected operation in a manner that benefits the adversary. |
CAPEC-17 | Using Malicious Files An attack of this type exploits a system's configuration that allows an adversary to either directly access an executable file, for example through shell access; or in a possible worst case allows an adversary to upload a file and then execute it. Web servers, ftp servers, and message oriented middleware systems which have many integration points are particularly vulnerable, because both the programmers and the administrators must be in synch regarding the interfaces and the correct privileges for each interface. |
CAPEC-39 | Manipulating Opaque Client-based Data Tokens In circumstances where an application holds important data client-side in tokens (cookies, URLs, data files, and so forth) that data can be manipulated. If client or server-side application components reinterpret that data as authentication tokens or data (such as store item pricing or wallet information) then even opaquely manipulating that data may bear fruit for an Attacker. In this pattern an attacker undermines the assumption that client side tokens have been adequately protected from tampering through use of encryption or obfuscation. |
CAPEC-402 | Bypassing ATA Password Security An adversary exploits a weakness in ATA security on a drive to gain access to the information the drive contains without supplying the proper credentials. ATA Security is often employed to protect hard disk information from unauthorized access. The mechanism requires the user to type in a password before the BIOS is allowed access to drive contents. Some implementations of ATA security will accept the ATA command to update the password without the user having authenticated with the BIOS. This occurs because the security mechanism assumes the user has first authenticated via the BIOS prior to sending commands to the drive. Various methods exist for exploiting this flaw, the most common being installing the ATA protected drive into a system lacking ATA security features (a.k.a. hot swapping). Once the drive is installed into the new system the BIOS can be used to reset the drive password. |
CAPEC-45 | Buffer Overflow via Symbolic Links This type of attack leverages the use of symbolic links to cause buffer overflows. An adversary can try to create or manipulate a symbolic link file such that its contents result in out of bounds data. When the target software processes the symbolic link file, it could potentially overflow internal buffers with insufficient bounds checking. |
CAPEC-5 | Blue Boxing This type of attack against older telephone switches and trunks has been around for decades. A tone is sent by an adversary to impersonate a supervisor signal which has the effect of rerouting or usurping command of the line. While the US infrastructure proper may not contain widespread vulnerabilities to this type of attack, many companies are connected globally through call centers and business process outsourcing. These international systems may be operated in countries which have not upgraded Telco infrastructure and so are vulnerable to Blue boxing. Blue boxing is a result of failure on the part of the system to enforce strong authorization for administrative functions. While the infrastructure is different than standard current applications like web applications, there are historical lessons to be learned to upgrade the access control for administrative functions. This attack pattern is included in CAPEC for historical purposes. |
CAPEC-51 | Poison Web Service Registry SOA and Web Services often use a registry to perform look up, get schema information, and metadata about services. A poisoned registry can redirect (think phishing for servers) the service requester to a malicious service provider, provide incorrect information in schema or metadata, and delete information about service provider interfaces. |
CAPEC-59 | Session Credential Falsification through Prediction This attack targets predictable session ID in order to gain privileges. The attacker can predict the session ID used during a transaction to perform spoofing and session hijacking. |
CAPEC-60 | Reusing Session IDs (aka Session Replay) This attack targets the reuse of valid session ID to spoof the target system in order to gain privileges. The attacker tries to reuse a stolen session ID used previously during a transaction to perform spoofing and session hijacking. Another name for this type of attack is Session Replay. |
CAPEC-647 | Collect Data from Registries An adversary exploits a weakness in authorization to gather system-specific data and sensitive information within a registry (e.g., Windows Registry, Mac plist). These contain information about the system configuration, software, operating system, and security. The adversary can leverage information gathered in order to carry out further attacks. |
CAPEC-668 | Key Negotiation of Bluetooth Attack (KNOB) An adversary can exploit a flaw in Bluetooth key negotiation allowing them to decrypt information sent between two devices communicating via Bluetooth. The adversary uses an Adversary in the Middle setup to modify packets sent between the two devices during the authentication process, specifically the entropy bits. Knowledge of the number of entropy bits will allow the attacker to easily decrypt information passing over the line of communication. |
CAPEC-76 | Manipulating Web Input to File System Calls An attacker manipulates inputs to the target software which the target software passes to file system calls in the OS. The goal is to gain access to, and perhaps modify, areas of the file system that the target software did not intend to be accessible. |
CAPEC-77 | Manipulating User-Controlled Variables This attack targets user controlled variables (DEBUG=1, PHP Globals, and So Forth). An adversary can override variables leveraging user-supplied, untrusted query variables directly used on the application server without any data sanitization. In extreme cases, the adversary can change variables controlling the business logic of the application. For instance, in languages like PHP, a number of poorly set default configurations may allow the user to override variables. |
CAPEC-87 | Forceful Browsing An attacker employs forceful browsing (direct URL entry) to access portions of a website that are otherwise unreachable. Usually, a front controller or similar design pattern is employed to protect access to portions of a web application. Forceful browsing enables an attacker to access information, perform privileged operations and otherwise reach sections of the web application that have been improperly protected. |
Name | Organization | Date | Date Release | Version |
---|---|---|---|---|
7 Pernicious Kingdoms | Draft 3 |
Name | Organization | Date | Comment |
---|---|---|---|
Eric Dalci | Cigital | updated Time_of_Introduction | |
Veracode | Suggested OWASP Top Ten 2004 mapping | ||
CWE Content Team | MITRE | updated Relationships, Other_Notes, Taxonomy_Mappings | |
CWE Content Team | MITRE | updated Common_Consequences, Description, Likelihood_of_Exploit, Name, Other_Notes, Potential_Mitigations, References, Relationships | |
CWE Content Team | MITRE | updated Potential_Mitigations | |
CWE Content Team | MITRE | updated Description, Related_Attack_Patterns | |
CWE Content Team | MITRE | updated Relationships | |
CWE Content Team | MITRE | updated Type | |
CWE Content Team | MITRE | updated Applicable_Platforms, Common_Consequences, Demonstrative_Examples, Detection_Factors, Modes_of_Introduction, Observed_Examples, Relationships | |
CWE Content Team | MITRE | updated Alternate_Terms, Detection_Factors, Potential_Mitigations, References, Relationships | |
CWE Content Team | MITRE | updated Potential_Mitigations | |
CWE Content Team | MITRE | updated Common_Consequences, References, Relationships | |
CWE Content Team | MITRE | updated Description | |
CWE Content Team | MITRE | Changed name and description; clarified difference between "access control" and "authorization." | |
CWE Content Team | MITRE | updated Background_Details, Demonstrative_Examples, Description, Name, Relationships | |
CWE Content Team | MITRE | updated Common_Consequences, Observed_Examples, Relationships | |
CWE Content Team | MITRE | updated Demonstrative_Examples, Potential_Mitigations, References, Related_Attack_Patterns, Relationships | |
CWE Content Team | MITRE | updated Potential_Mitigations | |
CWE Content Team | MITRE | updated Relationships | |
CWE Content Team | MITRE | updated Detection_Factors, Relationships, Taxonomy_Mappings | |
CWE Content Team | MITRE | updated Relationships | |
CWE Content Team | MITRE | updated Applicable_Platforms, Modes_of_Introduction, References, Relationships | |
CWE Content Team | MITRE | updated References, Relationships | |
CWE Content Team | MITRE | updated Related_Attack_Patterns | |
CWE Content Team | MITRE | updated Related_Attack_Patterns, Relationships | |
CWE Content Team | MITRE | updated References, Relationships | |
CWE Content Team | MITRE | updated Relationships | |
CWE Content Team | MITRE | updated Relationships | |
CWE Content Team | MITRE | updated Alternate_Terms | |
CWE Content Team | MITRE | updated Related_Attack_Patterns | |
CWE Content Team | MITRE | updated Relationships | |
CWE Content Team | MITRE | updated Relationships | |
CWE Content Team | MITRE | updated Observed_Examples | |
CWE Content Team | MITRE | updated Description, Potential_Mitigations | |
CWE Content Team | MITRE | updated References, Relationships | |
CWE Content Team | MITRE | updated Mapping_Notes |