Security readout for executives and security teams
Plain-English summary
CVE-2021-42303 is a Microsoft Azure RTOS elevation-of-privilege issue affecting version 6.0.0. It is rated medium, but availability impact is high in the supplied CVSS data. Exposure is most relevant where Azure RTOS 6.0.0 is embedded in deployed products or firmware.
Executive priority
Handle as a moderate embedded-software risk. Prioritize inventory first, then remediation for products where downtime or device instability would materially affect operations, customers, or safety-critical processes.
Technical view
The source bundle identifies an Azure Real Time Operating System 6.0.0 flaw with CVSS 3.1 score 6.6. The vector indicates local attack, low complexity, no privileges required, user interaction required, unchanged scope, low confidentiality and integrity impact, and high availability impact. CWE details are not provided.
Likely exposure
Likely exposure is limited to systems, devices, or firmware builds that include Microsoft Azure Real Time Operating System version 6.0.0. The CVSS vector suggests local attack conditions and required user interaction, not direct network exploitation.
Exploitation context
The provided sources do not show active exploitation. KEV is false, and the CVSS exploit maturity value is unproven. Treat exploitation status as unconfirmed unless Microsoft or CISA publishes stronger evidence.
Researcher notes
The public description is sparse and no CWE is listed. Analysis is mainly driven by the CVSS vector, affected product data, KEV status, and Microsoft advisory reference. Avoid assuming affected derivatives beyond confirmed Azure RTOS 6.0.0 use.
Mitigation direction
- Review Microsoft MSRC guidance for CVE-2021-42303.
- Apply the official vendor remediation where Azure RTOS 6.0.0 is present.
- Prioritize products where availability loss creates operational impact.
- Document affected firmware, owners, and update status.
- Monitor Microsoft advisories for any revised affected-version guidance.
Validation and detection
- Check SBOMs and build manifests for Azure RTOS 6.0.0.
- Identify deployed devices or products using affected firmware.
- Confirm whether vendor remediation is available and applied.
- Verify updated firmware no longer includes affected components.
- Record compensating controls where updates are not immediately possible.
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.
Privilege behavior lookup
The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-42303 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
- 6.6 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H/E:U/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:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H/E:U/RL:O/RC:C1.84.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.6MediumVector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H/E:U/RL:O/RC:C
Source materials
- CVE List V5 sourceCVE List V5
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-42303CVE 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.