Security readout for executives and security teams
Plain-English summary
CVE-2021-23416 is a cross-site scripting issue in the npm package curly-bracket-parser. If an application uses it as a template library with user-controlled input, malicious script content may be rendered to users. The supplied sources do not identify active exploitation or a fixed release.
Executive priority
Treat this as a moderate web application risk. Prioritize systems that render customer, partner, or public input through this package, especially internet-facing applications. No active exploitation is evidenced in the supplied sources.
Technical view
The package curly-bracket-parser fails to properly sanitize user input when used for templating. The CVSS 3.1 score is 5.4, with network attack vector, low complexity, no privileges required, required user interaction, and limited confidentiality and integrity impact.
Likely exposure
Exposure is most likely in JavaScript applications that include curly-bracket-parser and use it to process or render untrusted template input in a browser-visible context.
Exploitation context
The source bundle does not show CISA KEV listing or other evidence of active exploitation. Exploitation would depend on attacker-controlled input reaching the template rendering path and a user viewing the affected output.
Researcher notes
Affected product data is sparse: vendor is listed as n/a and affected versions are represented as all versions/package version 0 in the bundle. No CWE or patch version is provided, so validation should focus on actual usage paths.
Mitigation direction
- Inventory projects for curly-bracket-parser in package manifests and lockfiles.
- Check Snyk and vendor guidance for available remediation or replacement advice.
- Avoid passing untrusted input through this template parser.
- Escape or sanitize user-controlled output before browser rendering.
- Consider replacing the package if no maintained fixed version is available.
Validation and detection
- Confirm whether curly-bracket-parser is present in direct or transitive dependencies.
- Review call sites where template strings include user-controlled data.
- Verify rendered output cannot execute script in the browser.
- Run dependency scanning for CVE-2021-23416 or SNYK-JS-CURLYBRACKETPARSER-1297106.
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
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CVE-2021-23416 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/E:P
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:N/E:P2.82.5Primary 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/E:P
Source materials
- CVE List V5 sourceCVE List V5
- https://snyk.io/vuln/SNYK-JS-CURLYBRACKETPARSER-1297106CVE reference · x_refsource_MISC
- https://github.com/magynhard/curly-bracket-parser/blob/master/src/curly-bracket-parser/curly-bracket-parser.js%23L31CVE 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.