CVE-2021-47360

Local process hangs via deferred Binder fd cleanup

Published May 21, 2024 · Updated May 23, 2026

Denial of service in the Linux kernel Binder driver allows local users to hang processes by freeing buffers containing fd arrays. During BC_FREE_BUFFER handling, BINDER_TYPE_FDA cleanup queues fd closes as task work but fails to return the Binder thread to user space, so file objects can remain referenced indefinitely. A local process with access to a Binder device must trigger this cleanup path; the documented consequence is a process hang, not data access or modification.

CVSS severity5.5
Medium
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in the Linux kernel Binder driver allows local users to hang processes by freeing buffers containing fd arrays. During BC_FREE_BUFFER handling, BINDER_TYPE_FDA cleanup queues fd closes as task work but fails to return the Binder thread to user space, so file objects can remain referenced indefinitely. A local process with access to a Binder device must trigger this cleanup path; the documented consequence is a process hang, not data access or modification.

The record

CVE
CVE-2021-47360
Published
May 21, 2024
Updated
May 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-252, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 21, 2024CVE publishedPublication date reported by the CVE source.
  2. May 23, 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=27564d8d5d12d2ff197055346069c6bdbe08a8c2
  2. Affected versionversion=4.20.1 <4.21
  3. Affected versionversion=5.0
  4. Affected versionversion=80cd795630d6526ba729a089a435bf74a57af927 <5fdb55c1ac9585eb23bb2541d5819224429e103d
  5. Affected versionversion=80cd795630d6526ba729a089a435bf74a57af927 <aa2c274c279ff365a06a4cba263f04965895166e
  6. Affected versionversion=80cd795630d6526ba729a089a435bf74a57af927 <b95483d8d94b41fa31a84c1d86710b7907a37621
  7. Affected versionversion=80cd795630d6526ba729a089a435bf74a57af927 <d5b0473707fa53b03a5db0256ce62b2874bddbc7

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=27564d8d5d12d2ff197055346069c6bdbe08a8c2; version=4.20.1 <4.21; version=5.0; version=80cd795630d6526ba729a089a435bf74a57af927 <5fdb55c1ac9585eb23bb2541d5819224429e103d; version=80cd795630d6526ba729a089a435bf74a57af927 <aa2c274c279ff365a06a4cba263f04965895166e; version=80cd795630d6526ba729a089a435bf74a57af927 <b95483d8d94b41fa31a84c1d86710b7907a37621; version=80cd795630d6526ba729a089a435bf74a57af927 <d5b0473707fa53b03a5db0256ce62b2874bddbc7

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.

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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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-252Unchecked Return Value
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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