Security readout for executives and security teams
Plain-English summary
CVE-2021-38629 is a Windows information disclosure flaw in the Ancillary Function Driver for WinSock. It is not described as code execution or system takeover, but successful abuse could expose sensitive information. Treat it as a patching priority for affected Windows servers and workstations, especially shared or externally reachable environments.
Executive priority
Schedule remediation through normal vulnerability management, with faster handling for exposed servers and legacy Windows. The issue affects confidentiality, not integrity or availability, and no active exploitation is evidenced in the supplied sources.
Technical view
Microsoft lists this as an information disclosure vulnerability in the Windows Ancillary Function Driver for WinSock. CVSS 3.1 is 6.5 with network attack vector, low complexity, low privileges required, no user interaction, unchanged scope, and high confidentiality impact only.
Likely exposure
Exposure is likely on unpatched affected Windows versions listed by Microsoft, including Windows 10 releases, Windows Server 2008 through 2022, Windows 7 SP1, Windows 8.1, Windows RT 8.1, and Server Core installations. Risk is higher where low-privileged users or services can interact with network-facing Windows systems.
Exploitation context
The provided sources do not show CISA KEV listing or active exploitation. Microsoft’s CVSS vector marks exploit code maturity as unproven and remediation level as official fix. Do not assume exploitation in the wild from this bundle alone.
Researcher notes
Key signals are AV:N, AC:L, PR:L, UI:N, C:H, I:N, A:N. No CWE is provided in the bundle. Validation should focus on patch presence and affected Windows build coverage, not exploit reproduction.
Mitigation direction
- Apply Microsoft security updates referenced in the MSRC advisory for affected systems.
- Prioritize Windows servers, shared hosts, and internet-adjacent systems first.
- Retire or isolate unsupported Windows versions if updates are unavailable.
- Check Microsoft guidance for exact update packages and servicing requirements.
Validation and detection
- Inventory Windows versions and builds against the affected product list.
- Verify installed Microsoft updates address CVE-2021-38629 on each host.
- Confirm vulnerability scanner results clear after patching.
- Review exceptions for unsupported or isolated legacy systems.
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-2021-38629 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:L/UI:N/S:U/C:H/I:N/A:N/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:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C2.83.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.5MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/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-2021-38629CVE 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.