Security readout for executives and security teams
Plain-English summary
CVE-2021-47384 is a Linux kernel flaw in the w83793 hardware-monitoring driver. A specific device-read value can trigger a NULL pointer dereference, causing limited availability impact. The public record does not show data theft, privilege escalation, or confirmed exploitation.
Executive priority
Treat as a routine kernel maintenance item unless affected hardware is business-critical or exposed across many systems. Patch through normal Linux update channels, prioritizing systems where sensor-driver crashes could disrupt operations.
Technical view
The flaw is in the Linux hwmon w83793 driver. When a read temporary value matches a specific bit condition, the driver can dereference NULL. The upstream stable fix removes the unnecessary lm75[] structure field after devm_i2c_new_dummy_device() made it obsolete.
Likely exposure
Exposure is most likely on Linux systems running affected kernel builds with the w83793 hardware-monitoring driver present or usable. The bundle lists affected Linux kernel versions around 5.4 through 5.15 and provides stable kernel fix commits.
Exploitation context
The CVE has CVSS 5.3 with availability impact only. The source bundle marks CISA KEV as false and provides no cited evidence of active exploitation or public weaponization. Evidence is limited to the kernel fix record and CVE metadata.
Researcher notes
The public description attributes discovery to the Linux Driver Verification project. Root cause is a NULL pointer dereference from a driver state field that no longer served a purpose. No CWE is supplied in the bundle.
Mitigation direction
- Apply distribution kernel updates that include the referenced stable w83793 fix.
- Prioritize Linux systems using affected 5.4 through 5.15 kernel lines.
- Check vendor kernel advisories for exact fixed package versions.
- Reboot systems if required for the updated kernel to take effect.
Validation and detection
- Inventory Linux kernel versions across servers and appliances.
- Identify systems where the w83793 hwmon driver is present or loaded.
- Confirm installed kernels include one of the referenced stable fixes or vendor backports.
- Review monitoring for kernel crashes or availability incidents involving w83793.
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
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CVE-2021-47384 mapping review
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Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/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:N/UI:N/S:U/C:N/I:N/A:L3.91.4CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
5.3MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/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/6cb01fe630eaffc5a2c3f7364436caddba286623CVE reference, Linux
- https://git.kernel.org/stable/c/7c4fd5de39f273626a2b0f3a446d2cc85cd47616CVE reference, Linux
- https://git.kernel.org/stable/c/746011193f44f97f8784edcf8327c587946745fcCVE reference, Linux
- https://git.kernel.org/stable/c/dd4d747ef05addab887dc8ff0d6ab9860bbcd783CVE 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.