Security readout for executives and security teams
Plain-English summary
CVE-2021-23561 is a prototype pollution flaw in the JavaScript package comb. If an application uses comb's deepMerge() on attacker-influenced data, it may let unintended properties affect application objects, risking limited data integrity or availability impact.
Executive priority
Treat as a moderate dependency risk. It is not documented here as actively exploited, but affected applications should be inventoried and remediated where comb processes untrusted input.
Technical view
All versions of comb are listed as vulnerable through deepMerge(). The CVSS 3.1 score is 6.5: network reachable, low complexity, no privileges, no user interaction, with low integrity and availability impact and no confidentiality impact.
Likely exposure
Exposure is most likely in JavaScript applications that depend on comb and call deepMerge() with data from users, APIs, files, or other untrusted sources.
Exploitation context
The source bundle does not show CISA KEV listing or cited active exploitation. The CVSS vector indicates plausible remote exploitation when vulnerable merge logic is reachable through application input handling.
Researcher notes
Evidence is limited to the CVE record, CVE List data, and Snyk reference. No fixed version, exploit status, or vendor workaround is provided in the supplied bundle.
Mitigation direction
- Identify all direct and transitive uses of comb.
- Check Snyk, CVE, and package maintainer guidance for remediation status.
- Avoid passing untrusted data into comb deepMerge().
- Replace the dependency if no maintained fixed release is available.
- Add dependency monitoring for future comb advisories.
Validation and detection
- Search dependency manifests and lockfiles for comb.
- Trace whether application code calls deepMerge().
- Confirm whether deepMerge() handles externally influenced objects.
- Review SCA results for CVE-2021-23561 or SNYK-JS-COMB-1730083.
- Prioritize reachable server-side paths over unused dependency occurrences.
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-2021-23561 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
- 6.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
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:N/S:U/C:N/I:L/A:L3.92.5Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.5MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
Source materials
- CVE List V5 sourceCVE List V5
- https://snyk.io/vuln/SNYK-JS-COMB-1730083CVE 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.