dbcve.org
One FirmwareOperating system · Sonos

CVE-2023-27353

MEDIUM · 6.5 CVSS v3.1 Published 2023-04-20
Fix available
A fix is available. Upgrade to 11.7.1 / 15.1 or later.
See remediation →
70/100
Remediation priority · Elevated
No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
This vulnerability allows network-adjacent attackers to disclose sensitive information on affected installations of Sonos One Speaker 70.3-35220. Authentication is not required to exploit this vulnerability. The specific flaw exists within the msprox endpoint. The issue results from the lack of proper validation of user-supplied data, which can result in a read past the end of an allocated buffer. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of root. Was ZDI-CAN-19846.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

An out-of-bounds read vulnerability in the msprox endpoint of Sonos One Speaker firmware 70.3-35220 allows network-adjacent unauthenticated attackers to read past the end of an allocated buffer, exposing sensitive information. This can be chained with other vulnerabilities to achieve arbitrary code execution as root.

MitigationApply the vendor-supplied firmware update from Sonos. As a compensating control, restrict network access to the device using network segmentation to limit exposure to adjacent attackers.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
One FirmwareOperating system
Affected:= 70.3-35220
S1Application
Affected:< 11.7.1
S2Application
Affected:< 15.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the Sonos device model
    Check the device label, packaging, or access the Sonos app to view device information. Look for 'Sonos One' or confirm if it's running Sonos S1 or S2 controller software.
    Affected if The device is a Sonos One, or the controller software is Sonos S1 or S2.
  2. Determine the firmware version on Sonos One
    Open the Sonos app, go to Settings > System > About My System, or access the device web interface if enabled. Locate the firmware version field.
    Affected if The firmware version is exactly 70.3-35220.
  3. Determine the S1 controller version
    Open the Sonos S1 app, go to Settings > About Sonos, and note the software version displayed.
    Affected if The version is below 11.7.1 (for example, 11.7.0 or earlier).
  4. Determine the S2 controller version
    Open the Sonos S2 app, go to Settings > System > About My System, and note the software version displayed.
    Affected if The version is below 15.1 (for example, 15.0 or earlier).
  5. Verify network accessibility of the msprox service
    Use a network scanner or nmap to check if port 49154/tcp (commonly used by msprox) or the msprox service is reachable from the local network segment.
    Affected if The msprox endpoint is accessible from an adjacent network segment without authentication.

A user is affected if they own a Sonos One on firmware 70.3-35220, or use Sonos S1 before version 11.7.1, or Sonos S2 before version 15.1, and the device is accessible on the local network.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 11.7.1 / 15.1 or later
Fixed in 11.7.115.1
Interim mitigation

Apply the vendor-supplied firmware update from Sonos. As a compensating control, restrict network access to the device using network segmentation to limit exposure to adjacent attackers.

Recommended fix Moderate confidence

S1: >= 11.7.1 | S2: >= 15.1 | One: >= 11.7.1 (assuming same versioning)

  1. 1. Identify the Sonos device model (One, S1, or S2) in your environment
  2. 2. Check the current firmware version on each device through the Sonos app or web interface
  3. 3. For Sonos One devices running firmware version 70.3-35220, upgrade to version 11.7.1 or later
  4. 4. For S1 devices running versions lower than 11.7.1, upgrade to version 11.7.1 or later
  5. 5. For S2 devices running versions lower than 15.1, upgrade to version 15.1 or later
  6. 6. Verify the upgrade was successful by confirming the new firmware version
  7. 7. If automatic updates are not enabled, consider enabling them or establish a regular manual update schedule
Caveat Review release notes for major version jumps as Sonos S1 and S2 have different feature sets; ensure devices are compatible with desired firmware branch before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in One Firmware Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,060
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-27353 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data