Authorization Bypass Through User-Controlled SQL Primary Key
Incomplete Variant
Structure: Simple
Description
The product uses a database table that includes records that should not be accessible to an actor, but it executes a SQL statement with a primary key that can be controlled by that actor.
When a user can set a primary key to any value, then the user can modify the key to point to unauthorized records. Database access control errors occur when: - Data enters a program from an untrusted source. - The data is used to specify the value of a primary key in a SQL query. - The untrusted source does not have the permissions to be able to access all rows in the associated table.
Common Consequences 1
Scope: ConfidentialityIntegrityAccess Control
Impact: Read Application DataModify Application DataBypass Protection Mechanism
Detection Methods 1
Automated Static AnalysisHigh
Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)Potential Mitigations 2
Phase: Implementation
Assume all input is malicious. Use a standard input validation mechanism to validate all input for length, type, syntax, and business rules before accepting the data. Use an "accept known good" validation strategy.
Phase: Implementation
Use a parameterized query AND make sure that the accepted values conform to the business rules. Construct your SQL statement accordingly.
Demonstrative Examples 1
ID : DX-195
The following code uses a parameterized statement, which escapes metacharacters and prevents SQL injection vulnerabilities, to construct and execute a SQL query that searches for an invoice matching the specified identifier [1]. The identifier is selected from a list of all invoices associated with the current authenticated user.Code Example:
Bad
C#
c#The problem is that the developer has not considered all of the possible values of id. Although the interface generates a list of invoice identifiers that belong to the current user, an attacker can bypass this interface to request any desired invoice. Because the code in this example does not check to ensure that the user has permission to access the requested invoice, it will display any invoice, even if it does not belong to the current user.
Applicable Platforms
Languages:
SQL : Often
Technologies:
Database Server : Often
Modes of Introduction
Architecture and Design
Implementation
Related Weaknesses
Taxonomy Mapping
- Software Fault Patterns