Security readout for executives and security teams
Plain-English summary
CVE-2021-1642 is a Microsoft Windows privilege escalation flaw in AppX Deployment Extensions. An attacker who already has a low-privileged local account could potentially gain higher privileges. It is not described as remotely exploitable from the network, but successful exploitation could affect confidentiality, integrity, and availability.
Executive priority
Treat as a high-priority Windows patching item, especially on shared workstations, RDP-accessible systems, and servers where low-privileged users can authenticate. It is not KEV-listed in the supplied sources, so urgency is driven by privilege escalation impact and asset exposure.
Technical view
The supplied CVSS 3.1 vector is 7.8 high: AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Exposure is local, low complexity, requires low privileges, and needs no user interaction. Affected assets include multiple Windows 10, Windows Server 2016, Windows Server 2019, and semi-annual Server releases listed by Microsoft.
Likely exposure
Organizations may be exposed where affected Windows 10 or Windows Server builds remain unpatched: Windows 10 1607, 1803, 1809, 1909, 2004, 20H2; Windows Server 2016, 2019, 1909, 2004, and 20H2, including Server Core variants.
Exploitation context
The source bundle marks KEV as false and the CVSS exploit maturity as unproven. No provided source states active exploitation. This is most relevant after an attacker already has local code execution or credentials on an affected Windows system.
Researcher notes
The bundle provides limited root-cause detail beyond Microsoft’s title and CVSS vector. Do not infer a specific vulnerable component path or exploit technique. Validation should focus on affected OS matching, MSRC update status, and local privilege-escalation exposure assumptions.
Mitigation direction
- Apply the Microsoft security update identified in the MSRC advisory for each affected Windows build.
- Prioritize systems allowing local, RDP, VDI, or shared-user access.
- Confirm unsupported or out-of-lifecycle Windows builds have a vendor-supported remediation path.
- Reduce unnecessary local logon rights until patching is complete.
- Track exceptions through vulnerability management with owner and due date.
Validation and detection
- Inventory Windows versions against the affected product list in the CVE source bundle.
- Verify installed Microsoft security updates against the MSRC CVE-2021-1642 advisory.
- Confirm vulnerability scanner plugins identify CVE-2021-1642 as remediated after patching.
- Review high-risk shared endpoints and servers for remaining unpatched instances.
- Document any assets that cannot receive the vendor update.
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-2021-1642 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
- 7.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:H/A:H/E:U/RL:O/RC:C1.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
Source materials
- CVE List V5 sourceCVE List V5
- Windows AppX Deployment Extensions Elevation of Privilege VulnerabilityCVE reference · vendor-advisory
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-1642CVE reference · x_refsource_MISC, x_transferred
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.