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CVE Record

CVE-2021-40663: deep.assign npm package 0.0.0-alpha.0 is vulnerable to Improperly Controlled Modification of Object Prototy...

deep.assign npm package 0.0.0-alpha.0 is vulnerable to Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution').

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2021-40663 is a prototype pollution issue in the npm package deep.assign version 0.0.0-alpha.0. In plain terms, unsafe object merging could let attacker-controlled data alter shared JavaScript object behavior. The source bundle does not provide a CVSS score, known exploitation, or a confirmed patch.

Executive priority

Treat this as an inventory-driven dependency risk. It is not currently evidenced as actively exploited in the supplied bundle, but prototype pollution can support serious application compromise when reachable from untrusted input.

Technical view

The CVE describes improperly controlled modification of Object prototype attributes in deep.assign 0.0.0-alpha.0. Exposure depends on whether applications import this package and pass untrusted data into its deep assignment behavior. The bundle lists GitHub, npm, and NetApp references, but no exploit status, CWE, CVSS, or remediation details.

Likely exposure

Likely exposure is limited to JavaScript projects that directly or transitively depend on deep.assign 0.0.0-alpha.0. The source bundle does not identify specific affected applications or NetApp products, despite listing a NetApp advisory reference.

Exploitation context

The CVE is not listed as KEV, and the provided sources do not claim active exploitation. Prototype pollution can become serious when polluted properties influence authorization, configuration, serialization, or server-side logic, but application impact is context-dependent.

Researcher notes

Key missing evidence includes CVSS, CWE mapping, affected product list, exploit maturity, and patch details. Validate reachability before assigning high urgency. Do not assume impact beyond deep.assign 0.0.0-alpha.0 without dependency and code-path confirmation.

Mitigation direction

  • Inventory direct and transitive use of deep.assign 0.0.0-alpha.0.
  • Check npm, GitHub, and vendor advisories for fixed or recommended versions.
  • Replace the dependency if no maintained fixed version is available.
  • Review NetApp advisory applicability for any deployed NetApp products.
  • Prioritize remediation where untrusted input reaches object merge paths.

Validation and detection

  • Search dependency manifests and lockfiles for deep.assign 0.0.0-alpha.0.
  • Confirm whether application code passes user-controlled data into deep assignment logic.
  • Review SBOM and software composition analysis results for transitive exposure.
  • Check vendor advisories for product-specific impact statements.
  • Verify remediation by rerunning dependency scanning after changes.
Prepared
Confidence
medium
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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CVE-2021-40663 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
0Timeline events
0ADP providers
4Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.