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.
CVE-2023-4194
CVSS base score
5.5 (v3.1)
Severity
MEDIUM
Attack vector
Local
Weakness
CWE-843, CWE-863
Last modified
November 3, 2026
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
Affected products
linux linux kernel
redhat enterprise linux
fedoraproject fedora
debian debian linux
References
- access.redhat.com Third Party Advisory
- access.redhat.com Third Party Advisory
- bugzilla.redhat.com Issue Tracking, Third Party Advisory
- lore.kernel.org Mailing List, Patch, Vendor Advisory
- lore.kernel.org Mailing List, Patch, Vendor Advisory
- lore.kernel.org Mailing List, Patch, Vendor Advisory
- access.redhat.com Third Party Advisory
- access.redhat.com Third Party Advisory
- bugzilla.redhat.com Issue Tracking, Third Party Advisory
- lists.debian.org