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CVE-2021-23663

CVE-2021-23663: Prototype Pollution in sey

6.5

CVSS Score
3.1

Basic Information

CVE ID
CVE-2021-23663
GHSA ID
GHSA-wjpc-cgvw-xx23
EPSS Score
0.64032%
CWE
CWE-1321
Published
12/16/2021
Updated
9/8/2023
KEV Status
No
Technology
TechnologyJavaScript

Technical Details

CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
Package NameEcosystemVulnerable VersionsFirst Patched Version
seynpm<= 0.3.0

Vulnerability Intelligence
Miggo AIMiggo AI

Miggo AIRoot Cause Analysis

The vulnerability is explicitly attributed to the deepmerge function in all advisory sources. The PoC demonstrates prototype pollution through this function by merging a malicious payload containing proto properties. The file path is confirmed via the PoC's require('sey/lib/utils/deepmerge.js') statement. The function's recursive merging logic likely lacks checks for prototype-modifying properties like proto, constructor, or prototype.

Vulnerable functions

Only Mi**o us*rs **n s** t*is s**tion

WAF Protection Rules

WAF Rule

*ll v*rsions o* p**k*** `s*y` *r* vuln*r**l* to Prototyp* Pollution vi* t** `***pm*r**()` *un*tion.

Reasoning

T** vuln*r**ility is *xpli*itly *ttri*ut** to t** ***pm*r** *un*tion in *ll **visory sour**s. T** Po* **monstr*t*s prototyp* pollution t*rou** t*is *un*tion *y m*r*in* * m*li*ious p*ylo** *ont*inin* __proto__ prop*rti*s. T** *il* p*t* is *on*irm** vi