Security readout for executives and security teams
Plain-English summary
CVE-2021-28446 is a Microsoft Windows Portmapping information disclosure vulnerability. A local, low-privileged attacker could potentially expose sensitive information and affect availability on affected Windows clients and servers. Microsoft lists official remediation, but the provided sources do not describe exploit mechanics or known active exploitation.
Executive priority
Treat this as a high-priority patching item for affected Windows systems, especially servers and shared endpoints. There is no provided evidence of active exploitation, but the potential confidentiality and availability impact justifies timely remediation through standard Microsoft patch management.
Technical view
The CVSS vector is AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H with a 7.1 score. Exposure requires local access and low privileges, with no user interaction. The source bundle identifies many Windows and Windows Server versions, including Server Core installations, as affected.
Likely exposure
Organizations may be exposed where affected Windows desktop or server versions remain unpatched, especially legacy Windows 7, Windows Server 2008, Windows Server 2016, Windows Server 2019, and Windows 10 builds listed in the advisory data.
Exploitation context
The bundle marks KEV as false and CVSS exploit-code maturity as unproven. There is no cited evidence of active exploitation. Because the attack vector is local, this is more relevant for post-compromise, insider, shared-system, or chained attack scenarios than direct internet exploitation.
Researcher notes
The public bundle provides minimal root-cause detail and no CWE. Researchers should rely on MSRC and CVE records for authoritative scope. Some CPE entries appear duplicated or inconsistent in the bundle, so validate affectedness against Microsoft product guidance rather than CPE matching alone.
Mitigation direction
- Apply the Microsoft security update or remediation referenced by MSRC.
- Prioritize servers, shared workstations, and systems allowing local user access.
- Review Microsoft guidance for legacy or unsupported Windows versions.
- Restrict unnecessary local user privileges on affected systems.
- Track remediation through vulnerability management until CVE-2021-28446 clears.
Validation and detection
- Inventory Windows versions against the affected product list.
- Confirm installed patch status using Microsoft or enterprise patch tooling.
- Verify scanners no longer report CVE-2021-28446 on remediated hosts.
- Check whether Server Core installations are included in scope.
- Document exceptions for systems that cannot be patched immediately.
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-2021-28446 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
- High
- CVSS
- 7.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/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:L/UI:N/S:U/C:H/I:N/A:H/E:U/RL:O/RC:C1.85.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.1HighVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/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-2021-28446CVE 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.