CVE-2021-28952

Kernel memory corruption via undersized port arrays

Published Mar 20, 2021 · Updated Aug 3, 2024

A buffer overflow in the Linux kernel through 5.11.8 allows local users to corrupt kernel memory via an unexpected soundwire port ID. The Qualcomm SDM845 ASoC driver's sdm845_snd_data structure sizes stream_prepared and sruntime with SLIM_MAX_RX_PORTS even though AFE port IDs index them, permitting out-of-bounds writes above that limit. Exploitation requires local low-privileged access and the affected SDM845 soundwire path; successful corruption can compromise data or crash the system.

CVSS severity7.8
High
EPSS probability0.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A buffer overflow in the Linux kernel through 5.11.8 allows local users to corrupt kernel memory via an unexpected soundwire port ID. The Qualcomm SDM845 ASoC driver's sdm845_snd_data structure sizes stream_prepared and sruntime with SLIM_MAX_RX_PORTS even though AFE port IDs index them, permitting out-of-bounds writes above that limit. Exploitation requires local low-privileged access and the affected SDM845 soundwire path; successful corruption can compromise data or crash the system.

The record

CVE
CVE-2021-28952
Published
Mar 20, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-120, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 20, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
4.6NIST NVDAV:L/AC:L/Au:N/C:P/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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