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CVE Record

CVE-2021-47159: net: dsa: fix a crash if ->get_sset_count() fails

In the Linux kernel, the following vulnerability has been resolved: net: dsa: fix a crash if ->get_sset_count() fails If ds->ops->get_sset_count() fails then it "count" is a negative error code such as -EOPNOTSUPP. Because "i" is an unsigned int, the negative error code is type promoted to a very high value and the loop will corrupt memory until the system crashes. Fix this by checking for error codes and changing the type of "i" to just int.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This Linux kernel issue can crash systems using the Distributed Switch Architecture network stack when a driver reports an error while counting statistic strings. The available sources describe memory corruption leading to a system crash, not confirmed data theft or remote compromise.

Executive priority

Treat this as a targeted kernel stability risk, especially for network appliances and embedded Linux systems. Prioritize patch validation where DSA hardware is present; broad emergency response is not supported by the provided evidence.

Technical view

The bug is in Linux net/dsa statistics handling. A negative get_sset_count() error can be promoted during comparison with an unsigned loop variable, creating an extremely large loop bound and corrupting memory until the kernel crashes. Stable kernel commits add error checking and change the loop index type.

Likely exposure

Exposure is most likely on Linux systems using DSA-capable networking hardware or drivers in affected kernel ranges. General Linux fleets should validate kernel backports rather than relying only on upstream version numbers.

Exploitation context

The source bundle does not show CISA KEV listing, public exploitation, exploit code, or a remote attack path. The documented impact is memory corruption and crash when the vulnerable DSA code path receives a failing get_sset_count() result.

Researcher notes

Evidence is limited to the CVE record and upstream stable commit references. There is no CVSS, CWE, KEV entry, or exploit confirmation in the bundle. Validate exact affected status through downstream kernel backports and device configuration.

Mitigation direction

  • Update to a vendor kernel containing the referenced upstream stable fixes.
  • Confirm distribution advisories or changelogs include CVE-2021-47159 or the fix commits.
  • Prioritize systems using DSA switch hardware or related kernel drivers.
  • If patching is delayed, check vendor guidance for supported operational mitigations.

Validation and detection

  • Inventory Linux kernel versions and vendor backport status across affected hosts.
  • Identify hosts with DSA networking support, switch drivers, or embedded network appliances.
  • Verify installed kernel source or package changelog contains the referenced fix commits.
  • Review crash logs for kernel faults around net/dsa statistics paths.
Prepared
Confidence
medium
Sources
7

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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-2021-47159 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

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.

0CVSS vectors
3Timeline events
2ADP providers
6Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CVECVE Program Container
CISA-ADPCISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxbadf3ada60ab8f76f9488dc8f5c0c57f70682f5a, badf3ada60ab8f76f9488dc8f5c0c57f70682f5a, badf3ada60ab8f76f9488dc8f5c0c57f70682f5a, badf3ada60ab8f76f9488dc8f5c0c57f70682f5a, badf3ada60ab8f76f9488dc8f5c0c57f70682f5aunaffected
LinuxLinux4.7, 0, 4.19.193, 5.4.124, 5.10.42, 5.12.9, 5.13affected
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.