CVE-2023-0461

Published: 22 February 2023

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

From the Ubuntu Security Team

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.

Notes

reported by google kCTF, apparently.

for some kernels, an extra commit was applied as a follow
up commit: "UBUNTU: SAUCE: Fix inet_csk_listen_start after CVE-2023-0461"
to properly address an error code variable during the backport.
USN-5975-1 first publication included esm/xenial linux-gcp
version 4.15.0-1146.162~16.04.1 by mistake, please refer to USN-6007-1.

Status

Severity score breakdown

References

• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-0461
• https://ubuntu.com/security/notices/USN-5883-1
• https://ubuntu.com/security/notices/USN-5911-1
• https://ubuntu.com/security/notices/USN-5912-1
• https://ubuntu.com/security/notices/USN-5913-1
• https://ubuntu.com/security/notices/USN-5914-1
• https://ubuntu.com/security/notices/USN-5915-1
• https://ubuntu.com/security/notices/USN-5917-1
• https://ubuntu.com/security/notices/USN-5919-1
• https://ubuntu.com/security/notices/USN-5920-1
• https://ubuntu.com/security/notices/USN-5924-1
• https://ubuntu.com/security/notices/USN-5925-1
• https://ubuntu.com/security/notices/USN-5927-1
• https://ubuntu.com/security/notices/USN-5929-1
• https://ubuntu.com/security/notices/USN-5934-1
• https://ubuntu.com/security/notices/USN-5935-1
• https://ubuntu.com/security/notices/USN-5938-1
• https://ubuntu.com/security/notices/USN-5939-1
• https://ubuntu.com/security/notices/USN-5940-1
• https://ubuntu.com/security/notices/USN-5941-1
• https://ubuntu.com/security/notices/USN-5950-1
• https://ubuntu.com/security/notices/USN-5951-1
• https://ubuntu.com/security/notices/USN-5962-1
• https://ubuntu.com/security/notices/USN-5975-1
• https://ubuntu.com/security/notices/USN-5976-1
• https://ubuntu.com/security/notices/USN-6000-1
• https://ubuntu.com/security/notices/USN-6007-1
• NVD
• Launchpad
• Debian