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CWE WEAKNESSES  /  CWE-915

CWE-915

Improperly Controlled Modification of Dynamically-Determined Object Attributes

Base

What it is

The product receives input from an upstream component that specifies multiple attributes, properties, or fields that are to be initialized or updated in an object, but it does not properly control which attributes can be modified.

If the object contains attributes that were only intended for internal use, then their unexpected modification could lead to a vulnerability.This weakness is sometimes known by the language-specific mechanisms that make it possible, such as mass assignment, autobinding, or object injection.

Impact

IntegrityModify Application Data
IntegrityExecute Unauthorized Code or Commands
Other, IntegrityVaries by Context, Alter Execution Logic

Mitigations

  • [Implementation]If available, use features of the language or framework that allow specification of allowlists of attributes or fields that are allowed to be modified. If possible, prefer allowlists over denylists.For applications written with Ruby on Rails, use the attr_accessible (allowlist) or attr_protected (denylist) macros in each class that may be used in mass assignment.
  • [Architecture and Design, Implementation] If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.
  • [Implementation] For any externally-influenced input, check the input against an allowlist of internal object attributes or fields that are allowed to be modified.
  • [Implementation, Architecture and Design] Refactor the code so that object attributes or fields do not need to be dynamically identified, and only expose getter/setter functionality for the intended attributes.

Real-world CVE examples

  • CVE-2024-3283 — Application for using LLMs allows modification of a sensitive variable using mass assignment.
  • CVE-2012-2054 — Mass assignment allows modification of arbitrary attributes using modified URL.
  • CVE-2012-2055 — Source version control product allows modification of trusted key using mass assignment.
  • CVE-2008-7310 — Attackers can bypass payment step in e-commerce product.
  • CVE-2013-1465 — Use of PHP unserialize function on untrusted input allows attacker to modify application configuration.
  • CVE-2012-3527 — Use of PHP unserialize function on untrusted input in content management system might allow code execution.
  • CVE-2012-0911 — Use of PHP unserialize function on untrusted input in content management system allows code execution using a crafted cookie value.
  • CVE-2012-0911 — Content management system written in PHP allows unserialize of arbitrary objects, possibly allowing code execution.
  • CVE-2011-4962 — Content management system written in PHP allows code execution through page comments.
  • CVE-2009-4137 — Use of PHP unserialize function on cookie value allows remote code execution or upload of arbitrary files.
  • CVE-2007-5741 — Content management system written in Python interprets untrusted data as pickles, allowing code execution.
  • CVE-2011-2520 — Python script allows local users to execute code via pickled data.

Related weaknesses

Test & detect

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

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

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