Vulnerability record/PUBLISHED/Published Aug 7, 2023 13:19:44 UTC

CVE-2023-4194

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.

Base score5.5/ 10

SeverityMediumCVSS 3.1

Exploitability / impact

CVSS metric breakdown

Vector-derived attributes

Base severityMedium

Attack vectorLocalAV

Attack complexityLowAC

Privileges requiredLowPR

User interactionNoneUI

ScopeUnchangedS

Confidentiality impactNoneC

Integrity impactHighI

Availability impactNoneA

CVSS vector stringCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

CVSS communicates standardized severity and impact characteristics. It does not establish whether a system is exploitable in your specific environment.

Record context

CVE Numbering Authorityredhat

Last updatedNov 2, 2026 22:38:59 UTC

PublishedAug 7, 2023 13:19:44 UTC

ReservedAug 6, 2023 15:05:48 UTC

Credits

This issue was discovered by Laszlo Ersek (Red Hat).