Security readout for executives and security teams
Plain-English summary
CVE-2021-25948 affects the Node package expand-hash. Listed vulnerable versions can let attacker-controlled input pollute JavaScript object prototypes, causing denial of service and possibly remote code execution. Business urgency depends on whether this dependency is present and reachable from untrusted input.
Executive priority
Prioritize verification now. If the dependency is present in internet-facing or untrusted-input services, treat remediation as urgent because stated impact includes service disruption and possible code execution.
Technical view
The source bundle identifies prototype pollution in expand-hash versions 0.1.0 through 1.0.1. The public description states impact as denial of service with possible remote code execution. No CVSS, CWE, exploit details, or fixed version is provided in the supplied sources.
Likely exposure
Exposure is likely limited to Node.js applications that directly or transitively include expand-hash versions 0.1.0 through 1.0.1 and process untrusted data through it.
Exploitation context
The bundle does not show CISA KEV listing or active exploitation evidence. Treat exploitation as plausible only where vulnerable expand-hash code is reachable from user-controlled input.
Researcher notes
Evidence is sparse: affected versions and impact are identified, but no CVSS vector, CWE, proof of active exploitation, or fixed release is included. Validation should focus on reachability and dependency presence rather than assuming universal exposure.
Mitigation direction
- Inventory direct and transitive use of expand-hash in Node dependency manifests and lockfiles.
- Check vendor or advisory guidance for a fixed or maintained release before upgrading.
- If no fix is available, remove or replace expand-hash in affected applications.
- Prevent untrusted input from reaching expand-hash until remediation is complete.
- Prioritize internet-facing services and APIs that parse user-supplied structured data.
Validation and detection
- Confirm whether expand-hash versions 0.1.0 through 1.0.1 appear in application dependency trees.
- Map every identified instance to the service, route, or job that can invoke it.
- Review whether user-controlled input can flow into expand-hash processing.
- After remediation, confirm vulnerable versions are absent from lockfiles and deployed artifacts.
- Run relevant unit and regression tests for affected parsing or data-processing paths.
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.
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 lookupCVE-2021-25948 mapping review
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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://www.whitesourcesoftware.com/vulnerability-database/CVE-2021-25948CVE reference · x_refsource_MISC
- https://github.com/doowb/expand-hash/blob/556913f6c2f05848110b5b8261cfc78e5ce3dc77/index.js#L19CVE 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.