Security readout for executives and security teams
Plain-English summary
CVE-2018-3720 affects the assign-deep Node.js module before 0.4.7. A maliciously crafted object can change shared Object prototype behavior, potentially affecting many objects in an application. The sources do not provide CVSS scoring or evidence of active exploitation.
Executive priority
Treat this as a dependency hygiene and application exposure issue. Prioritize remediation where assign-deep is used in internet-facing services or workflows that merge untrusted data. The absence of KEV or CVSS data lowers certainty, not necessarily technical impact.
Technical view
The issue is a CWE-471 Modification of Assumed-Immutable Data flaw. assign-deep before 0.4.7 allowed __proto__ input to modify Object.prototype, adding or changing properties inherited by all objects. Impact depends on whether vulnerable code merges attacker-controlled object data.
Likely exposure
Exposure is likely limited to Node.js applications that include assign-deep before 0.4.7 directly or through dependencies, especially where untrusted JSON or object input is deeply merged. The source bundle does not list CPEs or broader product mappings.
Exploitation context
No source in the bundle states active exploitation, and the CVE is not listed as KEV. The public description confirms the primitive: modifying Object via __proto__. Business risk depends on reachable merge paths and how polluted properties influence application logic.
Researcher notes
The available evidence supports a prototype-modification class issue in assign-deep before 0.4.7, tied to CWE-471 and the referenced fix commit. The bundle lacks CVSS details, exploit-in-the-wild evidence, and product-specific deployment context, so validation should focus on dependency presence and reachable merge behavior.
Mitigation direction
- Upgrade assign-deep to 0.4.7 or later wherever present.
- Refresh lockfiles so transitive dependency resolution removes vulnerable versions.
- Audit deep-merge paths that process untrusted object data.
- Check vendor or package maintainer guidance for any additional remediation.
- Add input filtering for prototype-related keys where untrusted objects are merged.
Validation and detection
- Inventory package manifests and lockfiles for assign-deep versions before 0.4.7.
- Identify direct and transitive consumers of assign-deep in production services.
- Review code paths that deep-merge request, webhook, or file-parsed objects.
- Confirm tests cover rejection or safe handling of prototype-related object keys.
- Document whether vulnerable merge paths are externally reachable.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
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
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-471: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2018-3720 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://hackerone.com/reports/310707CVE reference · x_refsource_MISC
- https://github.com/jonschlinkert/assign-deep/commit/19953a8c089b0328c470acaaaf6accdfcb34da11CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Modification of Assumed-Immutable Data (MAID)
Modification of Assumed-Immutable Data (MAID) represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.