Use of Inner Class Containing Sensitive Data

Opis

Inner classes are translated into classes that are accessible at package scope and may expose code that the programmer intended to keep private to attackers.

Inner classes quietly introduce several security concerns because of the way they are translated into Java bytecode. In Java source code, it appears that an inner class can be declared to be accessible only by the enclosing class, but Java bytecode has no concept of an inner class, so the compiler must transform an inner class declaration into a peer class with package level access to the original outer class. More insidiously, since an inner class can access private fields in its enclosing class, once an inner class becomes a peer class in bytecode, the compiler converts private fields accessed by the inner class into protected fields.

Skutki

• Confidentiality

  Read Application Data

  "Inner Classes" data confidentiality aspects can often be overcome.

Zapobieganie

• Implementation

  Using sealed classes protects object-oriented encapsulation paradigms and therefore protects code from being extended in unforeseen ways.

• Implementation

  Inner Classes do not provide security. Warning: Never reduce the security of the object from an outer class, going to an inner class. If an outer class is final or private, ensure that its inner class is private as well.

Słabość nadrzędna

• CWE-668 Exposure of Resource to Wrong Sphere

Kiedy powstaje

• Implementation

Dotyczy

Java

Uwagi

Mobile 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 program is running.

Źródła

1. Seven Pernicious Kingdoms: A Taxonomy of Software Security Errors — Katrina Tsipenyuk, Brian Chess, Gary McGraw, NIST, 2005