Security readout for executives and security teams
Plain-English summary
This Linux kernel flaw can let a local, low-privileged user crash an affected system by triggering a null pointer dereference in ieee802154 address parsing. It is mainly an availability risk, not a data theft or privilege escalation issue based on the supplied sources.
Executive priority
Treat as routine-to-prioritized kernel maintenance. It can cause local denial of service, but the supplied evidence does not indicate remote compromise, data exposure, privilege escalation, or active exploitation.
Technical view
CVE-2021-47257 is a CWE-476 null dereference in the Linux kernel ieee802154 networking code. Incorrect mode selection for a given address type can lead to a null dereference. CVSS 3.1 is 5.5: local attack vector, low complexity, low privileges, no user interaction, high availability impact.
Likely exposure
Exposure is most relevant on Linux systems running affected kernel versions or carrying the vulnerable commit lineage, especially where ieee802154 support is present. The bundle lists affected versions including 4.4, 4.9.274, 4.14.238, 4.19.196, 5.4.127, 5.10.45, 5.12.12, and 5.13.
Exploitation context
The supplied sources do not show active exploitation, and KEV status is false. Exploitation requires local access with low privileges, so internet-facing remote exposure is not indicated by the bundle.
Researcher notes
The record is concise and does not provide exploit details. Analysis should focus on kernel version lineage, downstream backports, and whether ieee802154 code is reachable in the target environment. Do not infer affected distributions beyond vendor advisories.
Mitigation direction
- Apply vendor kernel updates containing the referenced stable Linux fixes.
- Prioritize shared, production, embedded, and appliance Linux systems where local users or workloads are untrusted.
- Check distribution advisories for backported fixes before relying only on upstream version numbers.
- Restrict local shell or workload access on systems that cannot be updated promptly.
Validation and detection
- Inventory Linux kernel versions across servers, endpoints, appliances, and embedded systems.
- Confirm whether ieee802154 kernel support is present or loaded on in-scope systems.
- Verify installed kernels include the relevant upstream stable fix or a vendor backport.
- Review vulnerability scanner findings against vendor advisories to avoid version-only false positives.
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-2021-47257 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/1f95741981c899c4724647291fec5faa3c777185CVE reference, Linux
- https://git.kernel.org/stable/c/c6998ccfefa652bac3f9b236821e392af43efa1eCVE reference, Linux
- https://git.kernel.org/stable/c/5f728ec65485625e30f46e5b4917ff023ad29ea0CVE reference, Linux
- https://git.kernel.org/stable/c/d0f47648b87b6d5f204cb7f3cbce6d36dab85a67CVE reference, Linux
- https://git.kernel.org/stable/c/c7836de2cadd88bc2f20f2c5a3d4ef4c73aef627CVE reference, Linux
- https://git.kernel.org/stable/c/fdd51e34f45311ab6e48d2147cbc2904731b9993CVE reference, Linux
- https://git.kernel.org/stable/c/9fdd04918a452980631ecc499317881c1d120b70CVE 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.