Security readout for executives and security teams
Plain-English summary
This Linux kernel issue is a memory leak in the MediaTek mt7921 Wi-Fi driver coredump worker. The documented impact is limited availability loss, not data theft or tampering. Treat it as a routine kernel remediation item unless the affected driver and kernel versions are present on business-critical systems.
Executive priority
Schedule remediation through normal kernel patch cycles. Escalate only where affected Linux systems are critical, exposed, or difficult to reboot, because the documented impact is availability degradation rather than compromise.
Technical view
CVE-2021-47031 resolves a possible memory leak in mt7921_coredump_work in the Linux kernel mt76/mt7921 driver. It is classified as CWE-401 with CVSS 3.1 score 4.3: network attack vector, low complexity, low privileges required, no user interaction, and low availability impact only.
Likely exposure
Exposure is most likely on Linux systems running affected kernel builds with mt76/mt7921 MediaTek Wi-Fi driver support. The source bundle identifies Linux 5.12 through 5.13 version data and kernel stable commits; downstream distribution backports must be checked directly.
Exploitation context
The source bundle does not show CISA KEV listing or active exploitation. The CVSS vector indicates privileges are required and expected impact is limited to availability. No public exploit status is established by the provided sources.
Researcher notes
Evidence is narrow: the CVE description only states a possible memory leak and references two kernel stable commits. No source in the bundle provides exploit details, observed attacks, or broader affected-product claims beyond Linux kernel version and commit data.
Mitigation direction
- Identify systems using affected Linux kernel builds and mt76/mt7921 driver support.
- Apply kernel updates containing the referenced stable fixes from your Linux vendor.
- Check distribution advisories for backported fixes matching the referenced kernel commits.
- Prioritize business-critical laptops, workstations, or appliances using MediaTek MT7921 Wi-Fi hardware.
Validation and detection
- Inventory kernel versions and loaded wireless drivers on Linux endpoints.
- Map vendor kernel packages to the referenced upstream stable commits.
- Confirm patched kernels no longer match the affected version range in advisories.
- Monitor affected systems for abnormal memory growth or availability symptoms until patched.
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-401: 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-2021-47031 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
- 4.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
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.
SSVC decision data
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:N/I:N/A:L2.81.4CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
4.3MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://git.kernel.org/stable/c/4811226374453607175ea057777faa7e7f752204CVE reference, Linux
- https://git.kernel.org/stable/c/782b3e86ea970e899f8e723db9f64708a15ca30eCVE reference, Linux
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.
Missing Release of Memory after Effective Lifetime
Missing Release of Memory after Effective Lifetime represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.