finalize() Method Declared Public
Incomplete Variant
Structure: Simple
Description
The product violates secure coding principles for mobile code by declaring a finalize() method public.
A product should never call finalize explicitly, except to call super.finalize() inside an implementation of finalize(). In mobile code situations, the otherwise error prone practice of manual garbage collection can become a security threat if an attacker can maliciously invoke a finalize() method because it is declared with public access.
Common Consequences 1
Scope: ConfidentialityIntegrityAvailability
Impact: Alter Execution LogicExecute Unauthorized Code or CommandsModify Application Data
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 1
Phase: Implementation
If you are using finalize() as it was designed, there is no reason to declare finalize() with anything other than protected access.
Demonstrative Examples 1
The following Java Applet code mistakenly declares a public finalize() method.
Code Example:
Bad
Java
javaMobile code, in this case a Java Applet, is code that is transmitted across a network and executed on a remote machine. Because mobile code developers have little if any control of the environment in which their code will execute, special security concerns become relevant. One of the biggest environmental threats results from the risk that the mobile code will run side-by-side with other, potentially malicious, mobile code. Because all of the popular web browsers execute code from multiple sources together in the same JVM, many of the security guidelines for mobile code are focused on preventing manipulation of your objects' state and behavior by adversaries who have access to the same virtual machine where your product is running.
Applicable Platforms
Languages:
Java : Undetermined
Modes of Introduction
Implementation
Related Weaknesses
Taxonomy Mapping
- The CERT Oracle Secure Coding Standard for Java (2011)
- Software Fault Patterns