CVE-2023-0461: Use-after-free vulnerability in the Linux Kernel

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.7% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-02-28 · updated 2026-06-17
Weakness: CWE-416

Description

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

Affected products

Linux kernel: from 4.13.0 before 4.14.303; from 4.19 before 4.19.270; from 5.4 before 5.4.229; from 5.10 before 5.10.163; from 5.15 before 5.15.88; from 6.0 before 6.0.19 — fixed in 4.14.303, 4.19.270, 5.10.163, 5.15.88, 5.4.229, 6.0.19

How to fix

Upgrade to a fixed version: Linux kernel 4.14.303, 4.19.270, 5.10.163, 5.15.88. Check the vendor advisory for mitigations.

References

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