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

Published Feb 23, 2023
·
Updated

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

Other sources

NVD 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 CONFIGTLS or CONFIGXFRMESPINTCP has to be configured, but the operation does not require any privilege. There is a use-after-free bug of icskulpdata of a struct inetconnectionsock. When CONFIGTLS is enabled, user can install a tls context (struct tlscontext) 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 TCPULP operation does not require any privilege.

Upstream commit: https://github.com/torvalds/linux/commit/2c02d41d71f90a5168391b6a5f2954112ba2307c

Red Hat

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 CONFIGTLS or CONFIGXFRMESPINTCP has to be configured, but the operation does not require any privilege.

There is a use-after-free bug of icskulpdata of a struct inetconnectionsock.

When CONFIGTLS is enabled, user can install a tls context (struct tlscontext) 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 TCPULP operation does not require any privilege.

We recommend upgrading past commit 2c02d41d71f90a5168391b6a5f2954112ba2307c

MITRE

Affected Software

23 affected componentsFixes available
redhat/kernel-rt<0:4.18.0-477.10.1.rt7.274.el8_8
0:4.18.0-477.10.1.rt7.274.el8_8
redhat/kernel<0:4.18.0-477.10.1.el8_8
0:4.18.0-477.10.1.el8_8
redhat/kernel<0:4.18.0-147.83.1.el8_1
0:4.18.0-147.83.1.el8_1
redhat/kernel<0:4.18.0-193.109.1.el8_2
0:4.18.0-193.109.1.el8_2
redhat/kernel-rt<0:4.18.0-193.109.1.rt13.160.el8_2
0:4.18.0-193.109.1.rt13.160.el8_2
redhat/kernel-rt<0:4.18.0-305.86.2.rt7.160.el8_4
0:4.18.0-305.86.2.rt7.160.el8_4
redhat/kernel<0:4.18.0-305.86.2.el8_4
0:4.18.0-305.86.2.el8_4
redhat/kernel<0:4.18.0-372.52.1.el8_6
0:4.18.0-372.52.1.el8_6
redhat/kernel<0:5.14.0-284.11.1.el9_2
0:5.14.0-284.11.1.el9_2
redhat/kernel-rt<0:5.14.0-284.11.1.rt14.296.el9_2
0:5.14.0-284.11.1.rt14.296.el9_2
redhat/kernel<0:5.14.0-70.58.1.el9_0
0:5.14.0-70.58.1.el9_0
redhat/kernel-rt<0:5.14.0-70.58.1.rt21.129.el9_0
0:5.14.0-70.58.1.rt21.129.el9_0
redhat/kernel<6.2
6.2
Linux Linux kernel>=4.13.0<4.14.303
Linux Linux kernel>=4.19<4.19.270
Linux Linux kernel>=5.4<5.4.229
Linux Linux kernel>=5.10<5.10.163
Linux Linux kernel>=5.15<5.15.88
Linux Linux kernel>=6.0<6.0.19
Linux Linux kernel>=6.1<6.1.5
Linux Linux kernel=6.2-rc1
Linux Linux kernel=6.2-rc2
debian/linux
5.10.223-15.10.234-16.1.129-16.1.135-16.12.25-16.12.27-1

Remediation

Information

To mitigate this issue, prevent module tls from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.

Event History

Feb 23, 2023
CVE Published
12:00 AM
Feb 28, 2023
CVE Published
via MITRE·02:23 PM
Data Sourced
via MITRE·02:23 PM
DescriptionSeverityWeakness
Mar 7, 2023
Data Sourced
via Red Hat·03:49 PM
DescriptionSeverityAffected Software
Jul 18, 2023
Data Sourced
10:22 AM
Description
May 2, 2025
Data Sourced
via Ubuntu·05:20 AM
RemedyDescriptionSeverityAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2023-0461?

CVE-2023-0461 is classified as a high-severity vulnerability due to its potential for privilege escalation.

2

How do I fix CVE-2023-0461?

To fix CVE-2023-0461, update your Linux kernel to version 4.18.0-477.10.1.rt7.274.el8_8 or later.

3

Which Linux kernel versions are affected by CVE-2023-0461?

CVE-2023-0461 affects Linux kernel versions prior to 4.18.0-477.10.1.rt7.274.el8_8.

4

Can CVE-2023-0461 be exploited remotely?

CVE-2023-0461 primarily allows local users to exploit the vulnerability, rather than being remotely exploitable.

5

What impact does CVE-2023-0461 have on system integrity?

CVE-2023-0461 can cause system crashes and potentially allow local users to escalate their privileges on the system.

Contact

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