Security readout for executives and security teams
Plain-English summary
CVE-2021-23443 is a stored or reflected XSS risk in edge.js before 5.3.2. If an application renders attacker-controlled data and that data arrives as an array, sanitization can be bypassed even when template escaping syntax is used. Business risk is user-session compromise or page manipulation in affected apps.
Executive priority
Prioritize remediation for internet-facing applications using edge.js with user-generated content. This is not a critical infrastructure emergency based on supplied evidence, but it can support account compromise or brand-damaging page manipulation if exploitable.
Technical view
The issue is a type confusion flaw in edge.js template rendering. Inputs expected as strings or SafeValue objects could be supplied as arrays, bypassing input sanitization around {{ }} rendering. The CVSS 3.1 score is 5.4 with network attack vector, low complexity, no privileges, and required user interaction.
Likely exposure
Exposure is limited to applications using edge.js versions before 5.3.2 and rendering user-influenced values through templates. Risk is higher where request data, stored profile fields, comments, or CMS content can reach templates as arrays.
Exploitation context
The provided sources do not indicate CISA KEV listing or active exploitation. Exploitation requires a victim interaction with a rendered page and application-specific control over template input shape.
Researcher notes
Focus review on data-flow into edge.js rendering where values may be arrays. The public description names type confusion and sanitization bypass, but the source bundle does not include broader exploit telemetry or affected application patterns.
Mitigation direction
- Upgrade edge.js to version 5.3.2 or later.
- Review dependency lockfiles for transitive edge.js usage.
- Check vendor and package advisories for any newer maintenance guidance.
- Normalize untrusted template inputs to expected scalar types before rendering.
- Avoid rendering user-controlled arrays directly in templates.
Validation and detection
- Identify all applications using edge.js and record installed versions.
- Confirm lockfiles resolve edge.js to 5.3.2 or later.
- Review templates that render user-controlled request or stored data.
- Test that array-shaped inputs are escaped or rejected by application validation.
- Check security scanners for SNYK-JS-EDGEJS-1579556 findings.
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.
CVE-2021-23443 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
- Medium
- CVSS
- 5.4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
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 vector scores
1 official scoreWe 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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N2.82.5Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.4MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://snyk.io/vuln/SNYK-JS-EDGEJS-1579556CVE reference · x_refsource_MISC
- https://github.com/edge-js/edge/commit/fa2c7fde86327aeae232752e89a6e37e2e469e21CVE 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.