Security readout for executives and security teams
Plain-English summary
A flaw in Moby HyperKit can let a local guest crash the host running it. This is a denial-of-service issue: the main business impact is disrupted virtualization workloads, not data theft or tampering based on the supplied sources.
Executive priority
Treat as a moderate availability risk. Remediate during the next planned maintenance cycle, faster where guest users are untrusted or virtualization outages would materially disrupt engineering or operations.
Technical view
HyperKit 0.20210107 and prior can dereference a null value in virtio.c when vc_cfgread is called without a null check. The CVSS vector is local, low complexity, no privileges, no user interaction, with high availability impact only.
Likely exposure
Exposure is limited to environments running Moby HyperKit 0.20210107 or earlier. Hosts running untrusted or tenant-controlled guests have higher operational risk because the reported impact is host crash from guest activity.
Exploitation context
The source bundle does not show CISA KEV listing or active exploitation evidence. The vulnerability is locally reachable in the virtualization context and affects availability; no confidentiality or integrity impact is reported.
Researcher notes
Evidence identifies CWE-476 null pointer dereference in virtio.c and a specific fixing commit. The supplied sources do not name a patched release, exploit activity, or affected downstream products, so avoid broad product assumptions.
Mitigation direction
- Update HyperKit to a build containing commit df0e46c7dbfd81a957d85e449ba41b52f6f7beb4.
- Check Moby HyperKit vendor guidance for any release-specific upgrade path.
- Avoid running untrusted guests on affected HyperKit hosts until remediated.
- Prioritize hosts supporting shared, production, or developer-critical virtualization workloads.
Validation and detection
- Inventory HyperKit versions and flag 0.20210107 or earlier.
- Confirm deployed builds include commit df0e46c7dbfd81a957d85e449ba41b52f6f7beb4.
- Review host crash logs for HyperKit-related availability events.
- Verify vulnerability scanners map findings to CVE-2021-32843 and affected HyperKit versions.
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.
CWE-476: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-32843 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
- 6.2 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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:N/S:U/C:N/I:N/A:H2.53.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.2MediumVector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Source materials
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.
NULL Pointer Dereference
NULL Pointer Dereference represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.