Security readout for executives and security teams
Plain-English summary
This is a Linux kernel bug in the Marvell Prestera network driver. The driver can read the wrong notifier structure during some network-device events, causing invalid memory access. The public bundle shows a KASAN stack out-of-bounds report, but does not provide CVSS, a practical impact rating, or evidence of active exploitation.
Executive priority
Treat as a targeted kernel reliability risk, not a broad emergency from the provided evidence. Prioritize remediation where Marvell Prestera hardware or drivers exist, and fold validation into normal kernel update governance.
Technical view
The Prestera netdev event handler accessed info->upper_dev before confirming the event carried netdev_notifier_changeupper_info. For events other than NETDEV_CHANGEUPPER, that field access can read beyond the expected stack object. The source identifies fixes in Linux stable commits and affected Linux versions around 5.14 through 5.16 metadata.
Likely exposure
Exposure appears limited to systems running affected Linux kernels with the Marvell Prestera driver present and relevant hardware or module use. General Linux servers without this driver or hardware are less likely exposed, but kernel packaging should be checked.
Exploitation context
The bundle does not show KEV listing, active exploitation, exploit availability, or attacker-controlled trigger details. Evidence is limited to a KASAN crash report during device registration involving udevd and the prestera module.
Researcher notes
Key uncertainty is exploitability. The public description proves an invalid read from incorrect notifier structure handling, but not privilege boundary crossing, remote reachability, or impact beyond crash or memory-safety violation. Validate against downstream kernel backports rather than version strings alone.
Mitigation direction
- Check vendor kernel advisories for CVE-2021-47102 applicability.
- Update to a kernel build containing the referenced stable fixes.
- Prioritize systems using Marvell Prestera switching hardware or the prestera module.
- If unavailable, seek vendor guidance on disabling or avoiding the affected driver.
Validation and detection
- Inventory kernels and identify hosts loading the prestera module.
- Compare kernel package changelogs against the referenced stable commits.
- Review boot and kernel logs for KASAN or prestera notifier crashes.
- Confirm network hardware uses Marvell Prestera before prioritizing remediation.
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-2021-47102 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.
SSVC decision data
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/5c553a0cd1263e4da5f220d80fa713fc3959c1d0CVE reference, Linux
- https://git.kernel.org/stable/c/2efc2256febf214e7b2bdaa21fe6c3c3146acdcbCVE 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.