// For flags

CVE-2023-1076

kernel: tap: tap_open(): correctly initialize socket uid

Severity Score

5.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

A flaw was found in the Linux Kernel. The tun/tap sockets have their socket UID hardcoded to 0 due to a type confusion in their initialization function. While it will be often correct, as tuntap devices require CAP_NET_ADMIN, it may not always be the case, e.g., a non-root user only having that capability. This would make tun/tap sockets being incorrectly treated in filtering/routing decisions, possibly bypassing network filters.

A flaw was found in the Linux kernel's TUN/TAP functionality. This issue could allow a local user to bypass network filters and get unauthorized access to some resources.

It was discovered that the Traffic-Control Index implementation in the Linux kernel did not properly perform filter deactivation in some situations. A local attacker could possibly use this to gain elevated privileges. Please note that with the fix for thisCVE, kernel support for the TCINDEX classifier has been removed. William Zhao discovered that the Traffic Control subsystem in the Linux kernel did not properly handle network packet retransmission in certain situations. A local attacker could use this to cause a denial of service.

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None
Attack Vector
Local
Attack Complexity
Low
Authentication
Single
Confidentiality
None
Integrity
Complete
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2023-02-27 CVE Reserved
  • 2023-03-27 CVE Published
  • 2025-02-24 CVE Updated
  • 2025-06-19 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-791: Incomplete Filtering of Special Elements
  • CWE-843: Access of Resource Using Incompatible Type ('Type Confusion')
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
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Affected