Bug 2391373 (CVE-2025-40779)

Summary:	CVE-2025-40779 kea: Kea crash upon interaction between specific client options and subnet selection
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	mosvald
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
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Doc Text:	A vulnerability was found in Kea. When an attacker who is an existing client with an assigned IP sends a crafted unicast packet directly to the server's IP and Kea cannot find any subnets that match that client's credentials, the server crashes causing a Denial of Service via assertion/NULL-path failure. This vulnerability does not persist for broadcast packets because they ignore such unverifiable clients.	Story Points:	---
Clone Of:		Environment:
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2392383
Bug Blocks:

Description OSIDB Bzimport 2025-08-27 21:01:21 UTC

If a DHCPv4 client sends a request with some specific options, and Kea fails to find an appropriate subnet for the client, the `kea-dhcp4` process will abort with an assertion failure.  This happens only if the client request is unicast directly to Kea; broadcast messages do not cause the problem.
This issue affects Kea versions 2.7.1 through 2.7.9, 3.0.0, and 3.1.0.

Comment 2 errata-xmlrpc 2025-11-11 19:12:24 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2025:21006 https://access.redhat.com/errata/RHSA-2025:21006