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

CVE-2020-7774

High
9.8/10

Summary

This affects the package y18n before 3.2.2, 4.x before 4.0.1, 5.0.x before 5.0.5 and 6.0.0-alpha.0. PoC by po6ix: const y18n = require('y18n')(); y18n.setLocale('__proto__'); y18n.updateLocale({polluted: true}); console.log(polluted); // true

  • LOW
  • NETWORK
  • HIGH
  • UNCHANGED
  • NONE
  • NONE
  • HIGH
  • HIGH

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.

References

Advisory Timeline

  • Published