GHSA-PQWC-3VHW-QCVQ
Vulnerability from github – Published: 2022-05-24 17:37 – Updated: 2024-02-01 21:00Overview
Prototype pollution vulnerability in 'shvl' versions 1.0.0 through 2.0.1 allows an attacker to cause a denial of service and may lead to remote code execution.
Details
The NPM module 'shvl' can be abused by Prototype Pollution vulnerability since the function 'set()' did not check for the type of object before assigning value to the property. Due to this flaw an attacker could create a non-existent property or able to manipulate the property which leads to Denial of Service or potentially Remote code execution.
PoC Details
The 'set()' function accepts four arguments object, path, val, obj. Due to the absence of validation, at values passed into path, val arguments, an attacker can supply a malicious value by adjusting the path value to include the __proto__ property. Since there is no validation before assigning property to check whether the assigned path is the Object's own property or not, the property isAdmin will be directly be assigned to the empty obj({}) thereby polluting the Object prototype. Later in the code, if there is a check to validate isAdmin the valued would be substituted as "true" as it had been polluted.
const shvl = require('shvl');
var obj = {}
console.log("Before : " + obj.isAdmin);
shvl.set(obj, '__proto__.isAdmin', true);
console.log("After : " + obj.isAdmin);
Affected Environments
1.0.0-2.0.1
Remediation
There are a couple of ways to mitigate prototype pollution vulnerabilities, for example: Most of the cases can be solved by freezing an object which doesn’t allow to add, remove, or change its properties. Validating the JSON input with schema validation, this guarantees that the JSON input contains only predefined attributes. We can change the objects, so they won’t have any prototype association by using “Object.create”.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 2.0.1"
},
"package": {
"ecosystem": "npm",
"name": "shvl"
},
"ranges": [
{
"events": [
{
"introduced": "1.0.0"
},
{
"fixed": "2.0.2"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2020-28278"
],
"database_specific": {
"cwe_ids": [
"CWE-1321"
],
"github_reviewed": true,
"github_reviewed_at": "2024-02-01T21:00:24Z",
"nvd_published_at": "2020-12-29T18:15:00Z",
"severity": "CRITICAL"
},
"details": "### Overview\nPrototype pollution vulnerability in \u0027shvl\u0027 versions 1.0.0 through 2.0.1 allows an attacker to cause a denial of service and may lead to remote code execution.\n\n### Details\nThe NPM module \u0027shvl\u0027 can be abused by Prototype Pollution vulnerability since the function \u0027set()\u0027 did not check for the type of object before assigning value to the property. Due to this flaw an attacker could create a non-existent property or able to manipulate the property which leads to Denial of Service or potentially Remote code execution.\n\n### PoC Details\nThe \u0027set()\u0027 function accepts four arguments `object, path, val, obj`. Due to the absence of validation, at values passed into `path, val` arguments, an attacker can supply a malicious value by adjusting the `path` value to include the `__proto__` property. Since there is no validation before assigning property to check whether the assigned `path` is the Object\u0027s own property or not, the property `isAdmin` will be directly be assigned to the empty obj({}) thereby polluting the Object prototype. Later in the code, if there is a check to validate `isAdmin` the valued would be substituted as \"true\" as it had been polluted.\n\n```js\nconst shvl = require(\u0027shvl\u0027);\nvar obj = {}\nconsole.log(\"Before : \" + obj.isAdmin);\nshvl.set(obj, \u0027__proto__.isAdmin\u0027, true);\nconsole.log(\"After : \" + obj.isAdmin);\n```\n\n### Affected Environments\n1.0.0-2.0.1\n\n### Remediation\nThere are a couple of ways to mitigate prototype pollution vulnerabilities, for example: Most of the cases can be solved by freezing an object which doesn\u2019t allow to add, remove, or change its properties. Validating the JSON input with schema validation, this guarantees that the JSON input contains only predefined attributes. We can change the objects, so they won\u2019t have any prototype association by using \u201cObject.create\u201d.",
"id": "GHSA-pqwc-3vhw-qcvq",
"modified": "2024-02-01T21:00:24Z",
"published": "2022-05-24T17:37:25Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2020-28278"
},
{
"type": "WEB",
"url": "https://github.com/robinvdvleuten/shvl/issues/34"
},
{
"type": "WEB",
"url": "https://github.com/robinvdvleuten/shvl/pull/36"
},
{
"type": "WEB",
"url": "https://github.com/robinvdvleuten/shvl/commit/513c0848774dfb114ad0d0554abf7927cfdd569e"
},
{
"type": "WEB",
"url": "https://web.archive.org/web/20210320222933/https://www.whitesourcesoftware.com/vulnerability-database/CVE-2020-28278"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
],
"summary": "shvl vulnerable to prototype pollution"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.