Modification of Assumed-Immutable Data (MAID)

The software does not properly protect an assumed-immutable element from being modified by an attacker.


This occurs when a particular input is critical enough to the functioning of the application that it should not be modifiable at all, but it is. Certain resources are often assumed to be immutable when they are not, such as hidden form fields in web applications, cookies, and reverse DNS lookups.


The following examples help to illustrate the nature of this weakness and describe methods or techniques which can be used to mitigate the risk.

Note that the examples here are by no means exhaustive and any given weakness may have many subtle varieties, each of which may require different detection methods or runtime controls.

Example One

In the code excerpt below, an array returned by a Java method is modified despite the fact that arrays are mutable.

String[] colors = car.getAllPossibleColors();
colors[0] = "Red";

See Also

SFP Secondary Cluster: Tainted Input to Environment

This category identifies Software Fault Patterns (SFPs) within the Tainted Input to Environment cluster (SFP27).

Data Processing Errors

Weaknesses in this category are typically found in functionality that processes data. Data processing is the manipulation of input to retrieve or save information.

Comprehensive CWE Dictionary

This view (slice) covers all the elements in CWE.

Weaknesses without Software Fault Patterns

CWE identifiers in this view are weaknesses that do not have associated Software Fault Patterns (SFPs), as covered by the CWE-888 view. As such, they represent gaps in...

Weaknesses Introduced During Implementation

This view (slice) lists weaknesses that can be introduced during implementation.

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