CWE-471

Modification of Assumed-Immutable Data (MAID)

Base

What it is

The product 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.

Impact

Integrity	Modify Application Data
Integrity	Unexpected State

Mitigations

[Architecture and Design, Operation, Implementation] When the data is stored or transmitted through untrusted sources that could modify the data, implement integrity checks to detect unauthorized modification, or store/transmit the data in a trusted location that is free from external influence.

Real-world CVE examples

CVE-2002-1757 — Relies on $PHP_SELF variable for authentication.
CVE-2005-1905 — Gain privileges by modifying assumed-immutable code addresses that are accessed by a driver.

Related weaknesses

CWE-664 (childof)

Test & detect

Browse all common weaknesses, check related exploited CVEs, or map to ATT&CK techniques.

Source: MITRE CWE. View on cwe.mitre.org →