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

> A use-after-free in the Linux Kernel allows local privilege escalation when TLS or ESPINTCP is enabled, requiring a kernel patch.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 28 Feb 2023
- **Updated:** 13 Feb 2025
- **Also known as:** AZL-25353, DEBIAN-CVE-2023-0461, GHSA-222x-4qhm-7h5f, RHSA-2023:1841, RHSA-2023:1923, UBUNTU-CVE-2023-0461

## What is CVE-2023-0461?

CVE-2023-0461 is a high-severity use after free vulnerability in Linux kernel, published on 28 Feb 2023. It can only be exploited from the same machine or local network, with no action from the victim.

### Official 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

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2023-0461?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `bpftool` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `bpftool-debuginfo` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `kernel` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `kernel-abi-stablelists` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `kernel-core` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `kernel-debug` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `kernel-debug-core` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `kernel-debug-debuginfo` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `kernel-debug-devel` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `kernel-debug-modules` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `kernel-debug-modules-extra` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `kernel-debuginfo` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `kernel-debuginfo-common-aarch64` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `kernel-debuginfo-common-ppc64le` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `kernel-debuginfo-common-s390x` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `kernel-debuginfo-common-x86_64` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `kernel-devel` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `kernel-doc` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `kernel-modules` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `kernel-modules-extra` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `kernel-tools` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `kernel-tools-debuginfo` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `kernel-tools-libs` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `kernel-zfcpdump` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `kernel-zfcpdump-core` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `kernel-zfcpdump-debuginfo` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `kernel-zfcpdump-devel` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `kernel-zfcpdump-modules` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `kernel-zfcpdump-modules-extra` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:4.18.0-372.52.1.el8_6 |
| `kpatch-patch-4_18_0-372_32_1` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:1-6.el8_6 |
| `kpatch-patch-4_18_0-372_32_1-debuginfo` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:1-6.el8_6 |
| `kpatch-patch-4_18_0-372_32_1-debugsource` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:1-6.el8_6 |
| `kpatch-patch-4_18_0-372_36_1` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:1-5.el8_6 |
| `kpatch-patch-4_18_0-372_36_1-debuginfo` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:1-5.el8_6 |
| `kpatch-patch-4_18_0-372_36_1-debugsource` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:1-5.el8_6 |
| `kpatch-patch-4_18_0-372_40_1` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:1-5.el8_6 |
| `kpatch-patch-4_18_0-372_40_1-debuginfo` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:1-5.el8_6 |
| `kpatch-patch-4_18_0-372_40_1-debugsource` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:1-5.el8_6 |
| `kpatch-patch-4_18_0-372_41_1` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:1-4.el8_6 |
| `kpatch-patch-4_18_0-372_41_1-debuginfo` | Red Hat:rhel_eus:8.6::baseos | All versions | 0:1-4.el8_6 |

Products: Linux kernel.

## How do I fix CVE-2023-0461?

Apply the vendor's patch.

## Is CVE-2023-0461 being exploited?

There is no known exploitation of CVE-2023-0461 in the wild and no public exploit code.

Public exploit code:

- https://github.com/b1nhack/CVE-2023-0461 (github_poc): https://github.com/b1nhack/CVE-2023-0461

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-0461 and fix it if it is affected.

What it is: CVE-2023-0461 is a high-severity use after free vulnerability in Linux kernel, published on 28 Feb 2023. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-0461 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2023-0461/ (Markdown: https://insights.sbomify.com/CVE-2023-0461/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-0461
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-0461
- OSV: https://osv.dev/vulnerability/CVE-2023-0461

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-0461/
Summaries are generated and may contain mistakes; the official description above is the record.