CVE-2023-1076: linux linux_kernel Incomplete Filtering of Special Elements

Vulnerability summary

CVE-2023-1076 is a medium (CVSS 5.5) Incomplete Filtering of Special Elements vulnerability in linux linux_kernel. EPSS estimates a 0.25% chance of exploitation in the next 30 days, higher than 16.9% of scored vulnerabilities.

Timeline

1. 27-03-2023
   PublishedVulnerability first disclosed.
2. 24-02-2025
   Last modifiedVulnerability information updated.

Description

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.

• CWE-791Incomplete Filtering of Special ElementsThe product receives data from an upstream component, but it does not completely filter special elements before sending it to a downstream component.
• CWE-843Access of Resource Using Incompatible TypeThe product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type.