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Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')


Severity High
Score 7.5/10


This affects the package nconf before 0.11.4. When using the memory engine, it is possible to store a nested JSON representation of the configuration. The .set() function, that is responsible for setting the configuration properties, is vulnerable to Prototype Pollution. By providing a crafted property, it is possible to modify the properties on the Object.prototype.

  • LOW
  • HIGH
  • NONE
  • NONE
  • NONE
  • NONE

CWE-1321 - Prototype Pollution

Prototype pollution is one of the lesser-known vulnerabilities. It allows attackers to abuse the rules of JavaScript by injecting properties into the general object “Object” in JS. Modifying the prototype of “Object” affects the behavior of all objects in the entire app, potentially resulting in denial of service, arbitrary code execution, cross-site scripting, etc.

Advisory Timeline

  • Published