---
title: CVE-2023-45236
description: Ubuntu is an open source software operating system that runs from the
  desktop, to the cloud, to all your internet connected things.
url: https://ubuntu.com/security/CVE-2023-45236
---

# CVE-2023-45236

Publication date 16 January 2024

Last updated 16 January 2026

---

Ubuntu priority

**Medium**

[Why this priority?](https://ubuntu.com/security/cves/about#priority )

## Cvss 3 Severity Score

**5.8 · Medium**

[Score breakdown](https://ubuntu.com/security/CVE-2023-45236#impact-score)

Toggle side navigation

## Description

EDK2's Network Package is susceptible to a predictable TCP Initial Sequence
Number. This
vulnerability can be exploited by an attacker to gain unauthorized
access and potentially lead to a loss of Confidentiality.

[Read the notes from the security team](https://ubuntu.com/security/CVE-2023-45236#notes)

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| edk2 | 25.10 questing | Not affected |
| 25.04 plucky | Not affected |
| 24.10 oracular | Ignored end of life, was needed |
| 24.04 LTS noble | Ignored see notes |
| 23.10 mantic | Ignored end of life, was needed |
| 23.04 lunar | Ignored end of life, was needs-triage |
| 22.04 LTS jammy | Ignored see notes |
| 20.04 LTS focal | Ignored end of standard support, was needed |
| 18.04 LTS bionic | Ignored end of standard support |
| 16.04 LTS xenial | Ignored end of standard support |
| 14.04 LTS trusty | Ignored end of standard support |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)
* [Patch details](https://ubuntu.com/security/CVE-2023-45236#patch-details)

## Notes

---

### [mdeslaur](https://launchpad.net/~mdeslaur)

This CVE was originally fixed by USN-7894-1, but it introduced a
regression in network boot and was reverted by USN-7894-2.
The fix for this issue results in a behavioural change that
requires guests to have a random network generator (virtio-rng).
Since this is a behavioural change, we are not able to fix this
CVE in stable releases. Marking as ignored.

### Patch details

For informational purposes only. We recommend not to cherry-pick updates. [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)

| Package | Patch details |
| --- | --- |
| edk2 | * Upstream:   <https://github.com/tianocore/edk2/pull/5582> * Upstream:   [1904a64](https://github.com/tianocore/edk2/commit/1904a64bcc18199738e5be183d28887ac5d837d7) |

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

5.8 · Medium

* Base metrics

  | Parameter | Value |
  | --- | --- |
  | Attack vector | Network |
  | Attack complexity | Low |
  | Privileges required | None |
  | User interaction | None |
  | Scope | Changed |
  | Confidentiality impact | Low |
  | Integrity impact | None |
  | Availability impact | None |
* Scores

  | Parameter | Value |
  | --- | --- |
  | Base score | 5.8 · Medium |
  | Exploitability score | - |
  | Impact score | - |

**Vector:** CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-45236)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2023-45236)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2023-45236)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2023-45236)

### Related Ubuntu Security Notices (USN)

+ [USN-7894-1](https://usn.ubuntu.com/USN-7894-1)
+ EDK II vulnerabilities
+ 26 November 2025

### Other references

* <https://blog.quarkslab.com/pixiefail-nine-vulnerabilities-in-tianocores-edk-ii-ipv6-network-stack.html>
* <https://www.openwall.com/lists/oss-security/2024/01/16/2>
* <https://github.com/tianocore/edk2/security/advisories/GHSA-hc6x-cw6p-gj7h>
* <https://www.cve.org/CVERecord?id=CVE-2023-45236>