CVE-2021-47442

Service interruption via leaked NFC command buffers

Published May 22, 2024 · Updated May 11, 2026

Memory leak in the Linux kernel NFC Digital Protocol stack from 3.13 allows local users to exhaust kernel memory through failed commands. digital_in_send_sdd_req() allocates an skb, but its error path does not free that buffer when digital_in_send_cmd() fails. Repeated failures require local low-privileged access to the NFC path and can deplete memory until service is interrupted.

CVSS severity5.5
Medium
EPSS probability0.23%
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 kernel NFC Digital Protocol stack from 3.13 allows local users to exhaust kernel memory through failed commands. digital_in_send_sdd_req() allocates an skb, but its error path does not free that buffer when digital_in_send_cmd() fails. Repeated failures require local low-privileged access to the NFC path and can deplete memory until service is interrupted.

The record

CVE
CVE-2021-47442
Published
May 22, 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 22, 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=2c66daecc4092e6049673c281b2e6f0d5e59a94c <071bdef36391958c89af5fa2172f691b31baa212
  2. Affected versionversion=2c66daecc4092e6049673c281b2e6f0d5e59a94c <291c932fc3692e4d211a445ba8aa35663831bac7
  3. Affected versionversion=2c66daecc4092e6049673c281b2e6f0d5e59a94c <2bde4aca56db9fe25405d39ddb062531493a65db
  4. Affected versionversion=2c66daecc4092e6049673c281b2e6f0d5e59a94c <50cb95487c265187289810addec5093d4fed8329
  5. Affected versionversion=2c66daecc4092e6049673c281b2e6f0d5e59a94c <6432d7f1d1c3aa74cfe8f5e3afdf81b786c32e86
  6. Affected versionversion=2c66daecc4092e6049673c281b2e6f0d5e59a94c <74569c78aa84f8c958f1334b465bc530906ec99a
  7. Affected versionversion=2c66daecc4092e6049673c281b2e6f0d5e59a94c <88c890b0b9a1fb9fcd01c61ada515e8b636c34f9
  8. Affected versionversion=2c66daecc4092e6049673c281b2e6f0d5e59a94c <fcce6e5255474ca33c27dda0cdf9bf5087278873
  9. Affected versionversion=3.13

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2c66daecc4092e6049673c281b2e6f0d5e59a94c <071bdef36391958c89af5fa2172f691b31baa212; version=2c66daecc4092e6049673c281b2e6f0d5e59a94c <291c932fc3692e4d211a445ba8aa35663831bac7; version=2c66daecc4092e6049673c281b2e6f0d5e59a94c <2bde4aca56db9fe25405d39ddb062531493a65db; version=2c66daecc4092e6049673c281b2e6f0d5e59a94c <50cb95487c265187289810addec5093d4fed8329; version=2c66daecc4092e6049673c281b2e6f0d5e59a94c <6432d7f1d1c3aa74cfe8f5e3afdf81b786c32e86; version=2c66daecc4092e6049673c281b2e6f0d5e59a94c <74569c78aa84f8c958f1334b465bc530906ec99a; version=2c66daecc4092e6049673c281b2e6f0d5e59a94c <88c890b0b9a1fb9fcd01c61ada515e8b636c34f9; version=2c66daecc4092e6049673c281b2e6f0d5e59a94c <fcce6e5255474ca33c27dda0cdf9bf5087278873; version=3.13

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-401Missing Release of Memory after Effective Lifetime
T1499.004Application 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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