Security readout for executives and security teams
Plain-English summary
This is a Linux kernel crash bug in the MediaTek MT7921 PCI Wi-Fi driver. A local user or local system action can trigger a race during device removal, causing a kernel NULL pointer dereference and likely system crash. Business impact is availability loss, not data theft or privilege escalation based on supplied evidence.
Executive priority
Prioritize as routine-to-expedited patching where affected Wi-Fi hardware exists. The credible impact is local denial of service, so urgency is higher for shared workstations, kiosks, or systems where local users can disrupt operations.
Technical view
The mt7921 PCI remove path freed the mt76 device before devm_free_irq completed. An interrupt handler could still run during teardown and dereference freed or NULL state, producing a kernel oops in mt7921_irq_handler. CVSS is 5.5 with local attack vector, low complexity, low privileges, and high availability impact.
Likely exposure
Exposure is likely limited to Linux systems using the mt76 mt7921e driver for MediaTek MT7921 PCI wireless hardware, especially affected 5.12-era through listed 5.19 kernel ranges. Systems without this hardware or driver are unlikely to be exposed.
Exploitation context
The source bundle does not show active exploitation, and KEV is false. The crash trace involves local device removal or driver unbind behavior during suspend/remove handling. Treat this as a local availability risk until vendor or distro advisories provide broader context.
Researcher notes
Evidence supports CWE-476 and an IRQ teardown race in mt7921_pci_remove. The bundle provides upstream stable commit references but no distro matrix, exploit report, or non-crash impact. Avoid claiming remote reachability or code execution from these sources.
Mitigation direction
- Update to a vendor kernel containing the referenced Linux stable fixes.
- Prioritize laptops, workstations, and VMs using mt7921e or MT7921 PCI Wi-Fi.
- Check Linux distribution advisories for fixed kernel package versions.
- Limit unnecessary local access to systems with affected kernels.
- Plan reboots where kernel updates are required.
Validation and detection
- Inventory systems for MediaTek MT7921 PCI Wi-Fi hardware or mt7921e driver use.
- Confirm running kernel versions against vendor fixed packages or referenced stable commits.
- Review kernel logs for mt7921_irq_handler NULL pointer dereference crashes.
- Verify CVE-2022-49476 is not listed as KEV in your vulnerability source.
- Track distro backports because version numbers alone may be misleading.
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-2022-49476 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
- 5.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/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.
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:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H1.83.6CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
5.5MediumVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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/09693f5b636fb3f6dd56fd943226fc1bbc600b51CVE reference, Linux
- https://git.kernel.org/stable/c/677e669973bf5460705bc65033445ea9f6615999CVE reference, Linux
- https://git.kernel.org/stable/c/ad483ed9dd5193a54293269c852a29051813b7bdCVE 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.
NULL Pointer Dereference
NULL Pointer Dereference represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.