CVE-2021-38544Public exploitNetwork attack vector

Speech disclosure via LED power side channel

Published Aug 11, 2021 · Updated Aug 4, 2024

Information disclosure in Sony SRS-XB33 and SRS-XB43 through 2021-08-09 allows remote attackers to recover speech signals via LED telemetry. The speakers connect the power indicator LED directly to the power line, so audio-driven power fluctuations modulate LED intensity that a telescope and electro-optical sensor can measure. Physical optical access and specialized sensing equipment are required; the demonstrated consequence is passive speech confidentiality loss without device modification or service interruption.

CVSS severity4.3
Medium
EPSS probability1.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Sony SRS-XB33 and SRS-XB43 through 2021-08-09 allows remote attackers to recover speech signals via LED telemetry. The speakers connect the power indicator LED directly to the power line, so audio-driven power fluctuations modulate LED intensity that a telescope and electro-optical sensor can measure. Physical optical access and specialized sensing equipment are required; the demonstrated consequence is passive speech confidentiality loss without device modification or service interruption.

The record

CVE
CVE-2021-38544
Published
Aug 11, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
Unavailable
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 11, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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 vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.9NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
4.3NVDAV:N/AC:M/Au:N/C:P/I:N/A:N

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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

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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