CVE & CISA-KEV Catalog

CVE-2021-47509

MEDIUM
5.5
CVSS v3
NVD

Description

In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: oss: Limit the period size to 16MB Set the practical limit to the period size (the fragment shift in OSS) instead of a full 31bit; a too large value could lead to the exhaust of memory as we allocate temporary buffers of the period size, too. As of this patch, we set to 16MB limit, which should cover all use cases.

How to fix

Remediation Available
linuxDebian
Fixed in:5.10.92-1CVE-2021-47509
Fixed in:5.15.15-1CVE-2021-47509
Fixed in:5.15.15-1CVE-2021-47509
Fixed in:5.15.15-1CVE-2021-47509

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorLocal
Attack ComplexityLow
Privileges RequiredLow
User InteractionNone
ScopeUnchanged

Impact

ConfidentialityNone
IntegrityNone
AvailabilityHigh

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Exploit Intelligence

0.24%probability of exploitation in 30 days
15thpercentile

Low risk: more likely to be exploited than 15% of all known CVEs.

References

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-09-29.