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CVE Record

CVE-2021-47332: ALSA: usx2y: Don't call free_pages_exact() with NULL address

In the Linux kernel, the following vulnerability has been resolved: ALSA: usx2y: Don't call free_pages_exact() with NULL address Unlike some other functions, we can't pass NULL pointer to free_pages_exact(). Add a proper NULL check for avoiding possible Oops.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysislow

Security readout for executives and security teams

Plain-English summary

CVE-2021-47332 is a Linux kernel bug in the ALSA usx2y audio driver. The kernel could try to free memory using a NULL address, causing a possible kernel Oops. The provided sources do not show remote exploitation, privilege escalation, or data theft.

Executive priority

Treat as routine kernel patch management unless the affected driver is used on sensitive or availability-critical Linux systems. There is no provided evidence of active exploitation or confirmed data compromise.

Technical view

The resolved issue adds a NULL check before calling free_pages_exact() in the ALSA usx2y code path. The CVE describes a possible Oops when a NULL pointer is passed. Public data provided has no CVSS score, CWE, or detailed attack prerequisites.

Likely exposure

Exposure appears limited to Linux systems running affected kernel versions where the ALSA usx2y driver code is present or usable. The source bundle does not establish internet-facing exposure or broad default exploitability.

Exploitation context

The bundle does not cite KEV listing or any public active exploitation. Based on the description, the documented impact is a possible kernel Oops, which most directly suggests availability risk rather than confirmed compromise.

Researcher notes

Evidence is sparse: no CVSS, CWE, exploit narrative, or prerequisites are provided. The strongest conclusion is a kernel NULL handling fix in ALSA usx2y with possible Oops impact, addressed by Linux stable commits.

Mitigation direction

  • Update to a vendor-supported Linux kernel containing the referenced stable fixes.
  • Check Linux distribution advisories for backported fixes for CVE-2021-47332.
  • Limit use of the ALSA usx2y driver where it is unnecessary.
  • Track this as kernel maintenance unless vendor guidance raises severity.

Validation and detection

  • Inventory Linux kernel versions against distribution CVE guidance.
  • Confirm whether systems can load or use the ALSA usx2y driver.
  • Verify patched source includes a NULL check before free_pages_exact().
  • Review crash logs for kernel Oops events involving usx2y code.
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-2021-47332 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
LinuxLinux36b8defc447627c3e91058c43941ec15d827556e, 36b8defc447627c3e91058c43941ec15d827556e, 36b8defc447627c3e91058c43941ec15d827556e, 36b8defc447627c3e91058c43941ec15d827556e, 36b8defc447627c3e91058c43941ec15d827556eunaffected
LinuxLinux5.2, 0, 5.4.134, 5.10.52, 5.12.19, 5.13.4, 5.14affected
Weakness

CWE details

No CWE listed

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