CVE-2021-47620

Journal flooding via late Bluetooth bounds check

Published Jun 20, 2024 · Updated Aug 5, 2026

Out-of-bounds reading in Linux kernel Bluetooth event handling allows physically proximate attackers to flood journals with false alerts. hci_le_adv_report_evt advanced its report pointer and read the next report header before checking that the header remained inside the packet buffer. Exposure requires a Bluetooth controller to deliver crafted LE advertising reports; the published concrete effect is false journal entries.

CVSS severity8.1
High
EPSS probability0.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Out-of-bounds reading in Linux kernel Bluetooth event handling allows physically proximate attackers to flood journals with false alerts. hci_le_adv_report_evt advanced its report pointer and read the next report header before checking that the header remained inside the packet buffer. Exposure requires a Bluetooth controller to deliver crafted LE advertising reports; the published concrete effect is false journal entries.

The record

CVE
CVE-2021-47620
Published
Jun 20, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-125
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 20, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=048acfa4daf167b007b6bd8bef474e90c2282a5f <305e92f525450f3e1b5f5c9dc7eadb152d66a082
  2. Affected versionversion=185c77cbb53bc7481acc5a0b4e6119bbe393d561 <5a539c08d743d9910631448da78af5e961664c0e
  3. Affected versionversion=24161b9c43de966789d5956428f45002d10f878e <835d3706852537bf92eb23eb8635b8dee0c0aa67
  4. Affected versionversion=2de0e6a71ceb056e17e4684dce8b7640367996f9 <bcea886771c3f22a590c8c8b9139a107bd7f1e1c
  5. Affected versionversion=3a56ef719f0b9682afb8a86d64b2399e36faa4e6 <899663be5e75dc0174dc8bda0b5e6826edf0b29a
  6. Affected versionversion=4.14.263 <4.14.265
  7. Affected versionversion=4.19.226 <4.19.228
  8. Affected versionversion=4.4.300 <4.4.302
  9. Affected versionversion=4.9.298 <4.9.300
  10. Affected versionversion=4a1491432394b22e585a185ffca49086e4046aae <8819f93cd4a443dfe547aa622b21f723757df3fb
  11. Affected versionversion=5.10.94 <5.10.96
  12. Affected versionversion=5.15.17 <5.15.19
  13. Affected versionversion=5.16.3 <5.16.5
  14. Affected versionversion=5.4.174 <5.4.176
  15. Affected versionversion=640a476e38fce6c70c738ac09e5167e34f570303 <5c968affa804ba98c3c603f37ffea6fba618025e
  16. Affected versionversion=7d4238edd3bf8b8c75571cc3b382bc10438ac588 <7889b38a7f21ed19314f83194622b195d328465c
  17. Affected versionversion=ffc9019bd991707701273c2e5d8aed472229fc4d <83d5196b65d1b29e27d7dd16a3b9b439fb1d2dba

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=048acfa4daf167b007b6bd8bef474e90c2282a5f <305e92f525450f3e1b5f5c9dc7eadb152d66a082; version=185c77cbb53bc7481acc5a0b4e6119bbe393d561 <5a539c08d743d9910631448da78af5e961664c0e; version=24161b9c43de966789d5956428f45002d10f878e <835d3706852537bf92eb23eb8635b8dee0c0aa67; version=2de0e6a71ceb056e17e4684dce8b7640367996f9 <bcea886771c3f22a590c8c8b9139a107bd7f1e1c; version=3a56ef719f0b9682afb8a86d64b2399e36faa4e6 <899663be5e75dc0174dc8bda0b5e6826edf0b29a; version=4.14.263 <4.14.265; version=4.19.226 <4.19.228; version=4.4.300 <4.4.302; version=4.9.298 <4.9.300; version=4a1491432394b22e585a185ffca49086e4046aae <8819f93cd4a443dfe547aa622b21f723757df3fb; version=5.10.94 <5.10.96; version=5.15.17 <5.15.19; version=5.16.3 <5.16.5; version=5.4.174 <5.4.176; version=640a476e38fce6c70c738ac09e5167e34f570303 <5c968affa804ba98c3c603f37ffea6fba618025e; version=7d4238edd3bf8b8c75571cc3b382bc10438ac588 <7889b38a7f21ed19314f83194622b195d328465c; version=ffc9019bd991707701273c2e5d8aed472229fc4d <83d5196b65d1b29e27d7dd16a3b9b439fb1d2dba

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
8.1kernel.orgCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/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)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo