@phun-ky/defaults-deep Has a Prototype Pollution issue via Unsafe Recursive Property Merging

NVD Description

### Impact A prototype pollution vulnerability exists in @phun-ky/defaults-deep prior to version 2.0.5. The library recursively merged user-supplied objects without filtering unsafe property names such as `__proto__`, `constructor`, and `prototype`. An attacker able to supply crafted input could cause properties to be written to `Object.prototype`, resulting in prototype pollution affecting all objects within the running process. Applications that pass untrusted input to `defaultsDeep()` may be impacted. Depending on how the application uses merged objects, this could lead to unexpected behavior, logic bypasses, denial of service, or other security issues. ### Patches This issue has been fixed in version 2.0.5. Users should upgrade to version 2.0.5 or later. The fix prevents unsafe prototype-related keys (`__proto__`, `constructor`, and `prototype`) from being processed during recursive merge operations and includes regression tests covering known prototype pollution vectors. ### Workarounds Users unable to upgrade should ensure that untrusted input is sanitized before being passed to `defaultsDeep()`. At a minimum, applications should reject or remove the following property names from all levels of user-controlled objects: - `__proto__` - `constructor` - `prototype` Upgrading to a patched version remains the recommended mitigation.

Affected Packages (1)