CVE-2021-47344

Local service interruption via leaked USB request block

Published May 21, 2024 · Updated May 11, 2026

Memory leak in the Linux zr364xx USB camera driver allows local users to exhaust kernel memory and interrupt service. The zr364xx_start_readpipe function returns after usb_submit_urb fails without freeing the allocated USB request block. Reachability requires the zr364xx driver and a USB request submission failure during device initialization; repeated failures can deplete memory.

CVSS severity5.5
Medium
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory leak in the Linux zr364xx USB camera driver allows local users to exhaust kernel memory and interrupt service. The zr364xx_start_readpipe function returns after usb_submit_urb fails without freeing the allocated USB request block. Reachability requires the zr364xx driver and a USB request submission failure during device initialization; repeated failures can deplete memory.

The record

CVE
CVE-2021-47344
Published
May 21, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-401, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 21, 2024CVE publishedPublication date reported by the CVE source.
  2. May 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.6.32
  2. Affected versionversion=ccbf035ae5de4c535160fc99f73feb44cc55b534 <021c294dff030f3ba38eb81e400ba123db32ecbc
  3. Affected versionversion=ccbf035ae5de4c535160fc99f73feb44cc55b534 <0a045eac8d0427b64577a24d74bb8347c905ac65
  4. Affected versionversion=ccbf035ae5de4c535160fc99f73feb44cc55b534 <0edd6759167295ea9969e89283b81017b4c688aa
  5. Affected versionversion=ccbf035ae5de4c535160fc99f73feb44cc55b534 <5f3f81f1c96b501d180021c23c25e9f48eaab235
  6. Affected versionversion=ccbf035ae5de4c535160fc99f73feb44cc55b534 <b0633051a6cb24186ff04ce1af99c7de18c1987e
  7. Affected versionversion=ccbf035ae5de4c535160fc99f73feb44cc55b534 <bbc80a972a3c5d7eba3f6c9c07af8fea42f5c513
  8. Affected versionversion=ccbf035ae5de4c535160fc99f73feb44cc55b534 <c57b2bd3247925e253729dce283d6bf6abc9339d
  9. Affected versionversion=ccbf035ae5de4c535160fc99f73feb44cc55b534 <c57bfd8000d7677bf435873b440eec0c47f73a08
  10. Affected versionversion=ccbf035ae5de4c535160fc99f73feb44cc55b534 <d69b39d89f362cfeeb54a68690768d0d257b2c8f

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2.6.32; version=ccbf035ae5de4c535160fc99f73feb44cc55b534 <021c294dff030f3ba38eb81e400ba123db32ecbc; version=ccbf035ae5de4c535160fc99f73feb44cc55b534 <0a045eac8d0427b64577a24d74bb8347c905ac65; version=ccbf035ae5de4c535160fc99f73feb44cc55b534 <0edd6759167295ea9969e89283b81017b4c688aa; version=ccbf035ae5de4c535160fc99f73feb44cc55b534 <5f3f81f1c96b501d180021c23c25e9f48eaab235; version=ccbf035ae5de4c535160fc99f73feb44cc55b534 <b0633051a6cb24186ff04ce1af99c7de18c1987e; version=ccbf035ae5de4c535160fc99f73feb44cc55b534 <bbc80a972a3c5d7eba3f6c9c07af8fea42f5c513; version=ccbf035ae5de4c535160fc99f73feb44cc55b534 <c57b2bd3247925e253729dce283d6bf6abc9339d; version=ccbf035ae5de4c535160fc99f73feb44cc55b534 <c57bfd8000d7677bf435873b440eec0c47f73a08; version=ccbf035ae5de4c535160fc99f73feb44cc55b534 <d69b39d89f362cfeeb54a68690768d0d257b2c8f

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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

Weakness, pattern, technique

CWE-401Missing Release of Memory after Effective Lifetime
T1499.004Endpoint Denial of Service: Application or System Exploitation

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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