Security readout for executives and security teams
Plain-English summary
This is a Linux kernel memory corruption issue in the Lantiq network driver receive ring. Under allocation or DMA mapping failure, the driver could program an invalid descriptor address. The published severity is high because successful exploitation could affect confidentiality, integrity, and availability, but the CVSS vector is local and requires low privileges.
Executive priority
Treat as high priority where Lantiq driver systems remain on affected kernels, especially infrastructure with local user access. Broader enterprise urgency depends on whether those kernels and that driver are actually deployed. No cited source confirms exploitation in the wild.
Technical view
The flaw is in Linux net/lantiq RX ring handling. When skb allocation or DMA mapping fails, an invalid address may be placed into a descriptor instead of reusing the previous skb and mapping while dropping the packet. Stable kernel commits resolve the behavior and increment the RX drop counter.
Likely exposure
Exposure is most likely on Linux systems running affected kernel versions with the Lantiq network driver in use. The source bundle lists Linux kernel versions including 4.20, 5.4.124, 5.10.42, 5.12.9, and 5.13 as affected, but downstream backport status must be checked per vendor distribution.
Exploitation context
The provided sources do not show active exploitation, and KEV is false. CVSS indicates local attack vector, low privileges required, no user interaction, and high potential impact across confidentiality, integrity, and availability. Evidence in the bundle does not establish remote exploitability.
Researcher notes
The key evidence is the kernel fix description: allocation or DMA mapping failure could write an invalid descriptor address, causing memory corruption. The affected-version data is sparse and downstream kernels may be patched independently, so validation should focus on commit or package-fix presence, not version strings alone.
Mitigation direction
- Apply Linux stable kernel updates containing the referenced Lantiq RX ring fix.
- Check distribution advisories for backported fixes in supported kernel packages.
- Prioritize systems using the Lantiq network driver on affected kernel builds.
- If patch status is unclear, request guidance from the kernel or distribution vendor.
Validation and detection
- Inventory Linux kernel versions on systems using the Lantiq network driver.
- Compare installed kernel changelogs against the referenced stable commits.
- Confirm vendor packages include the RX ring memory corruption fix.
- Document systems still running affected kernels for remediation tracking.
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
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ATT&CK lookup starting points
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CWE-770: Exact CWE lookup
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Open ATT&CK lookupCVE-2021-47137 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
- High
- CVSS
- 7.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:H/I:H/A:H1.85.9CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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/8bb1077448d43a871ed667520763e3b9f9b7975dCVE reference, Linux
- https://git.kernel.org/stable/c/5ac72351655f8b033a2935646f53b7465c903418CVE reference, Linux
- https://git.kernel.org/stable/c/46dd4abced3cb2c912916f4a5353e0927db0c4a2CVE reference, Linux
- https://git.kernel.org/stable/c/c7718ee96dbc2f9c5fc3b578abdf296dd44b9c20CVE 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.
Allocation of Resources Without Limits or Throttling
Allocation of Resources Without Limits or Throttling represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.