Security readout for executives and security teams
Plain-English summary
This is a Linux kernel Wi-Fi denial-of-service issue. On systems using the mac80211 subsystem with certain 5 GHz-only wireless devices, a malicious nearby radio frame can trigger a NULL pointer dereference and crash affected kernel code.
Executive priority
Treat this as a targeted availability risk for Linux wireless systems, especially operational devices where reboot or service loss matters. It is not presented as remotely internet-exploitable in the provided sources.
Technical view
CVE-2021-38206 affects Linux kernel mac80211 before 5.12.13. The reported flaw is a NULL pointer dereference in radiotap parsing when handling injected frames with 802.11a rates on 5 GHz-only devices. The public bundle identifies an upstream kernel commit and Linux 5.12.13 changelog entry as the fix evidence.
Likely exposure
Exposure is likely limited to Linux systems with affected pre-5.12.13 mac80211 code and relevant 5 GHz-only Wi-Fi hardware. Practical attack positioning appears local wireless range, not internet-facing, based on the described injection vector.
Exploitation context
The source bundle does not show active exploitation, and KEV is false. The described impact is denial of service, not code execution or data theft. No exploit maturity, CVSS score, or distro-specific advisories are included.
Researcher notes
Evidence is narrow but specific: Linux mac80211 before 5.12.13, 5 GHz-only device condition, radiotap parser NULL dereference, and denial of service by injected wireless frames. No CWE, CVSS, affected CPEs, or downstream vendor package mapping are provided.
Mitigation direction
- Update to Linux kernel 5.12.13 or a vendor-backported fixed kernel.
- Check distribution advisories for the matching CVE and package status.
- Prioritize mobile, wireless, embedded, and access-point-adjacent Linux deployments.
- Where updates are delayed, assess whether affected Wi-Fi hardware can be disabled or replaced.
Validation and detection
- Inventory Linux systems using mac80211-based wireless adapters.
- Confirm kernel version or vendor package includes the upstream fix commit.
- Identify systems with 5 GHz-only Wi-Fi hardware before prioritizing testing.
- Review crash logs for wireless or radiotap-related NULL pointer dereference events.
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-2021-38206 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
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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 and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.13CVE reference · x_refsource_MISC
- https://github.com/torvalds/linux/commit/bddc0c411a45d3718ac535a070f349be8eca8d48CVE 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.