CVE-2023-0461

A use-after-free flaw was found in the Linux kernel’s TLS protocol functionality in how a user installs a tls context (struct tls_context) on a connected TCP socket. This flaw allows a local user to crash or potentially escalate their privileges on the system.

There is a use-after-free vulnerability in the Linux Kernel which can be exploited to achieve local privilege escalation. To reach the vulnerability kernel configuration flag CONFIG_TLS or CONFIG_XFRM_ESPINTCP has to be configured, but the operation does not require any privilege. There is a use-after-free bug of icsk_ulp_data of a struct inet_connection_sock. When CONFIG_TLS is enabled, user can install a tls context (struct tls_context) on a connected tcp socket. The context is not cleared if this socket is disconnected and reused as a listener. If a new socket is created from the listener, the context is inherited and vulnerable. The setsockopt TCP_ULP operation does not require any privilege. We recommend upgrading past commit 2c02d41d71f90a5168391b6a5f2954112ba2307c

Davide Ornaghi discovered that the netfilter subsystem in the Linux kernel did not properly handle VLAN headers in some situations. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. It was discovered that the Upper Level Protocol (ULP) subsystem in the Linux kernel did not properly handle sockets entering the LISTEN state in certain protocols, leading to a use-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code.