CVE-2023-45236

Publication date 16 January 2024

Last updated 16 January 2026

Ubuntu priority

Cvss 3 Severity Score

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

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 see notes
	18.04 LTS bionic	Ignored see notes
	16.04 LTS xenial	Ignored see notes
	14.04 LTS trusty	Ignored end of standard support

Notes

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?

Package	Patch details
edk2	Upstream: https://github.com/tianocore/edk2/pull/5582 Upstream: 1904a64

Severity score breakdown

Parameter	Value
Base score	5.8 · Medium
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Changed
Confidentiality	Low
Integrity impact	None
Availability impact	None
Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N

References

Related Ubuntu Security Notices (USN)

USN-7894-1
EDK II vulnerabilities
26 November 2025