---
id: CVE-2023-4194
title: >-
  Kernel: tap: tap_open(): correctly initialize socket uid next fix of i_uid to
  current_fsuid
summary: >-
  A flaw was found in the Linux kernel's TUN/TAP functionality. This issue could
  allow a local user to bypass network filters and gain unauthorized access to
  some resources. The original patches fixing CVE-2023-1076 are incorrect or
  incomp…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N'
cvssSource: cna
cwe:
  - CWE-843
vendor: Red Hat
product: kernel
affected:
  - kernel (all versions)
  - kernel (all versions)
  - kernel
  - kernel
  - kernel-rt
  - kernel (all versions)
  - kernel-rt (all versions)
  - kernel-rt (all versions)
  - redhat-virtualization-host
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2025-06-03T16:14:49.416502Z'
published: '2023-08-07'
updated: '2026-11-03'
sourceUpdated: '2026-11-03T04:04:37.918Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2023-4194'
references:
  - url: 'https://access.redhat.com/errata/RHSA-2023:6583'
    label: 'RHSA-2023:6583'
  - url: 'https://access.redhat.com/security/cve/CVE-2023-4194'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2229498'
    label: RHBZ#2229498
  - url: 'https://lore.kernel.org/all/20230731164237.48365-1-lersek@redhat.com/'
  - url: 'https://lore.kernel.org/all/20230731164237.48365-2-lersek@redhat.com/'
  - url: 'https://lore.kernel.org/all/20230731164237.48365-3-lersek@redhat.com/'
tags:
  - cve.org
epss: 0.00267
epssPercentile: 0.1899
ingestedAt: '2026-11-05T19:30:42.889Z'
---

## Overview

A flaw was found in the Linux kernel's TUN/TAP functionality. This issue could allow a local user to bypass network filters and gain unauthorized access to some resources. The original patches fixing CVE-2023-1076 are incorrect or incomplete. The problem is that the following upstream commits - a096ccca6e50 ("tun: tun_chr_open(): correctly initialize socket uid"), - 66b2c338adce ("tap: tap_open(): correctly initialize socket uid"), pass "inode->i_uid" to sock_init_data_uid() as the last parameter and that turns out to not be accurate.

## Affected

- `kernel (all versions)`
- `kernel (all versions)`
- `kernel`
- `kernel`
- `kernel-rt`
- `kernel (all versions)`
- `kernel-rt (all versions)`
- `kernel-rt (all versions)`
- `redhat-virtualization-host`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.