What’s Vulnerable › Vulnerabilities
CVE-2023-4194: Kernel: tap: tap_open(): correctly initialize socket uid next fix of i_uid to current_fsuid
- Severity: medium (CVSS 5.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.3% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2023-08-07 · updated 2026-06-17
- Weakness: CWE-843
Description
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 products
- Debian Linux: 10.0, 11.0, 12.0
- Fedoraproject Fedora: 37, 38
- Linux kernel: through 6.4; 6.5-rc1, 6.5-rc2, 6.5-rc3, 6.5-rc4
- Red Hat Enterprise Linux: 8.0, 9.0
References
- https://access.redhat.com/errata/RHSA-2023:6583
- https://access.redhat.com/security/cve/CVE-2023-4194
- https://bugzilla.redhat.com/show_bug.cgi?id=2229498
- https://lore.kernel.org/all/20230731164237.48365-1-lersek@redhat.com/
- https://lore.kernel.org/all/20230731164237.48365-2-lersek@redhat.com/
- https://lore.kernel.org/all/20230731164237.48365-3-lersek@redhat.com/
- https://access.redhat.com/errata/RHSA-2023:6583
- https://access.redhat.com/security/cve/CVE-2023-4194
- https://bugzilla.redhat.com/show_bug.cgi?id=2229498
- https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/344H6HO6SSC4KT7PDFXSDIXKMKHISSGF/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/3TYLSJ2SAI7RF56ZLQ5CQWCJLVJSD73Q/
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