CVE-2023-31083Public exploit

System crash via HCI UART protocol race

Published Apr 24, 2023 · Updated Nov 3, 2025

A race condition in the Linux kernel 6.2 Bluetooth HCI UART driver allows local users to cause a system crash through concurrent ioctls. In hci_uart_tty_ioctl, HCIUARTSETPROTO marks HCI_UART_PROTO_SET before assigning hu->proto, while a concurrent HCIUARTGETPROTO dereferences the still-null pointer. Reaching the race requires local access and CAP_NET_ADMIN in the initial user namespace; successful exploitation interrupts the host by crashing the kernel.

CVSS severity4.7
Medium
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A race condition in the Linux kernel 6.2 Bluetooth HCI UART driver allows local users to cause a system crash through concurrent ioctls. In hci_uart_tty_ioctl, HCIUARTSETPROTO marks HCI_UART_PROTO_SET before assigning hu->proto, while a concurrent HCIUARTGETPROTO dereferences the still-null pointer. Reaching the race requires local access and CAP_NET_ADMIN in the initial user namespace; successful exploitation interrupts the host by crashing the kernel.

The record

CVE
CVE-2023-31083
Published
Apr 24, 2023
Updated
Nov 3, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-476, CWE-362, T1499
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Apr 24, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.5SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.7NIST NVDCVSS:3.1/AV:L/AC:H/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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
T1499Endpoint Denial of Service

Public exploit references

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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