LiveActive security incident?Get immediate response
CVE Record

CVE-2021-47502: ASoC: codecs: wcd934x: handle channel mappping list correctly

In the Linux kernel, the following vulnerability has been resolved: ASoC: codecs: wcd934x: handle channel mappping list correctly Currently each channel is added as list to dai channel list, however there is danger of adding same channel to multiple dai channel list which endups corrupting the other list where its already added. This patch ensures that the channel is actually free before adding to the dai channel list and also ensures that the channel is on the list before deleting it. This check was missing previously, and we did not hit this issue as we were testing very simple usecases with sequence of amixer commands.

UnknownCVSS not scoredNot KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This Linux kernel issue affects handling of audio channel mapping in the wcd934x codec driver. A logic error could corrupt internal lists when the same channel is added to multiple DAI channel lists. Business impact appears limited to systems using this driver, but severity is not provided in the source record.

Executive priority

Treat as a targeted kernel maintenance item, not an emergency, unless your fleet includes devices using the wcd934x audio codec. Track vendor kernel updates and fold remediation into normal patch cycles while confirming exposure on embedded or device-specific Linux builds.

Technical view

The vulnerable ASoC wcd934x code did not verify channel list state before add or delete operations. The resolved patch checks that a channel is free before adding it to a DAI list and checks membership before deletion, preventing list corruption under more complex mixer command sequences.

Likely exposure

Exposure is most likely on Linux systems with affected kernel versions and the wcd934x ASoC codec path enabled. Systems without this codec driver or audio use case are less likely exposed. The source bundle does not provide CPEs or a complete affected-version matrix.

Exploitation context

The bundle reports no CISA KEV listing and provides no evidence of active exploitation or public exploit activity. The description references discovery during testing of amixer command sequences, but does not describe an attacker path, required privileges, or impact severity.

Researcher notes

Key unknowns are impact severity, exploitability, and exact fixed-version boundaries across distributions. The source evidence supports a kernel list-corruption bug in wcd934x channel mapping logic, fixed by state checks around list add and delete operations.

Mitigation direction

  • Update to a vendor-supported kernel containing the referenced stable fixes.
  • Check distribution or device-vendor advisories for backported CVE-2021-47502 fixes.
  • Prioritize systems that enable or load the wcd934x ASoC codec driver.
  • Do not deploy direct kernel patches outside normal vendor support processes without validation.

Validation and detection

  • Inventory Linux kernel versions against the CVE record and vendor advisories.
  • Confirm whether the wcd934x ASoC codec driver is compiled, enabled, or loaded.
  • Review kernel package changelogs for the referenced stable commit identifiers.
  • Test audio codec functionality after updating vendor kernels.
Prepared
Confidence
medium
Sources
5

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

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cve · low confidence lookup

CVE-2021-47502 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
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
4Source 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

CISA-ADPCISA ADP Vulnrichment
other:ssvc
CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxdd9eb19b567303e4b92747dcfb5deedb182af111, dd9eb19b567303e4b92747dcfb5deedb182af111, dd9eb19b567303e4b92747dcfb5deedb182af111unaffected
LinuxLinux5.6, 0, 5.10.85, 5.15.8, 5.16affected
Weakness

CWE details

No CWE listed

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