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CVE Record

CVE-2021-23449: Sandbox Bypass

This affects the package vm2 before 3.9.4 via a Prototype Pollution attack vector, which can lead to execution of arbitrary code on the host machine.

CriticalCVSS 9.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysiscritical

Security readout for executives and security teams

Plain-English summary

CVE-2021-23449 is a critical sandbox bypass in the JavaScript package vm2 before 3.9.4. A flaw tied to prototype pollution could let code meant to be isolated break out and execute arbitrary code on the host machine, creating full confidentiality, integrity, and availability risk.

Executive priority

Treat this as urgent for any internet-facing or multi-tenant service using vm2 for JavaScript sandboxing. The business risk is host compromise from code that the application expected to contain safely.

Technical view

The source bundle describes vm2 before 3.9.4 as vulnerable to prototype pollution leading to arbitrary host code execution. The CVSS 3.1 score is 9.8 with network attack vector, low complexity, no privileges, no user interaction, and high impact across CIA.

Likely exposure

Exposure is most likely in Node.js applications that depend on vm2 before 3.9.4, especially where vm2 evaluates untrusted, tenant-supplied, plugin, or automation JavaScript. Transitive dependencies may also matter.

Exploitation context

The bundle does not show CISA KEV listing or cited evidence of active exploitation. The CVSS vector indicates low-friction remote exploitation potential, and the vulnerability is publicly documented by Snyk, GitHub issue, commit, release, and NetApp advisory links.

Researcher notes

Key evidence is strong for package, impact, and fixed release. The bundle does not provide CWE classification, detailed affected version ranges beyond before 3.9.4, or confirmed active exploitation. Focus analysis on prototype pollution reachability and vm2 call sites.

Mitigation direction

  • Upgrade vm2 to version 3.9.4 or later where the fix was released.
  • Check vendor advisories for any product-specific remediation guidance.
  • Prioritize systems that execute untrusted JavaScript through vm2.
  • Rebuild and redeploy artifacts after dependency updates.
  • Restrict untrusted script execution until patched.

Validation and detection

  • Review package manifests and lockfiles for vm2 versions before 3.9.4.
  • Check SBOMs and dependency scanners for direct or transitive vm2 usage.
  • Identify runtime paths where vm2 handles untrusted JavaScript.
  • Confirm deployed containers and build artifacts include the fixed dependency.
  • Verify vendor products against NetApp or relevant supplier advisories.
Prepared
Confidence
high
Sources
7

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

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

description · low confidence lookup

Execution behavior lookup

The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2021-23449 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Critical
CVSS
9.8 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P

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.

1CVSS vectors
0Timeline events
0ADP providers
6Source links

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
9.8CVSS 3.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P3.95.9Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

9.8Critical
CVSS 3.1 vector shape for CVE-2021-23449Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/avm2unspecifiedListed
Weakness

CWE details

No CWE listed

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