Security readout for executives and security teams
Plain-English summary
CVE-2021-42307 is an information disclosure issue in Microsoft Edge Chromium-based. The business impact described by the sources is limited data exposure, not system takeover or service disruption. Successful exploitation requires user interaction, which lowers urgency compared with unauthenticated remote code execution.
Executive priority
Treat this as a routine browser security update with moderate priority. It does not indicate active exploitation in the provided evidence, but browser exposure is broad and user interaction is a realistic path in phishing or web-based scenarios.
Technical view
The CVSS 3.1 vector is AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N, scoring 4.3. It is network-accessible, low complexity, requires no privileges, requires user interaction, and affects confidentiality only at low impact. The supplied affected product is Microsoft Edge Chromium-based.
Likely exposure
Exposure is most likely on endpoints running affected Microsoft Edge Chromium-based versions. The source bundle does not provide a detailed version range beyond the affected product entry, so inventory should be checked against Microsoft’s advisory rather than inferred broadly.
Exploitation context
The bundle does not show CISA KEV listing or active exploitation. The CVSS temporal vector includes E:P, indicating proof-of-concept exploit maturity, but the provided sources do not document real-world exploitation or weaponized details.
Researcher notes
The available data is sparse: no CWE, no detailed root cause, and no exploit mechanics are provided. Validation should stay focused on version exposure and vendor advisory alignment. Avoid assuming impact beyond low confidentiality exposure described by CVSS.
Mitigation direction
- Review Microsoft’s advisory for the affected and fixed Edge builds.
- Update Microsoft Edge Chromium-based to a vendor-supported fixed release.
- Keep browser auto-update enabled across managed endpoints.
- Prioritize users handling sensitive data or high-risk browsing workflows.
Validation and detection
- Inventory installed Microsoft Edge versions on managed endpoints.
- Compare installed builds with Microsoft’s CVE-2021-42307 advisory.
- Confirm update deployment through endpoint management reporting.
- Check whether unsupported or pinned Edge installations remain present.
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.
CVE-2021-42307 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
- 4.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N/E:P/RL:O/RC:C
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:N/A:N/E:P/RL:O/RC:C2.81.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
4.3MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N/E:P/RL:O/RC:C
Source materials
- CVE List V5 sourceCVE List V5
- Microsoft Edge (Chromium-based) Information Disclosure VulnerabilityCVE reference · vendor-advisory
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.