Bug 2508232

Summary:	CVE-2024-5300 snapd: Canonical snapd: Information disclosure of system password hashes via AppArmor bypass [fedora-all]
Product:	[Fedora] Fedora	Reporter:	Thibault Guittet <tguittet>
Component:	snapd	Assignee:	Zygmunt Krynicki <me>
Status:	NEW ---	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	45	CC:	go-sig, maciek.borzecki, me, ngompa13
Target Milestone:	---	Keywords:	Security, SecurityTracking
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:	{"flaws": ["254c5fd4-dae2-4ee3-932f-f95ba9e38977"]}
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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:
Bug Blocks:	2503660

Description Thibault Guittet 2026-07-28 21:24:02 UTC

Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

An access control bypass and information disclosure vulnerability exists in the base AppArmor security profile configuration of Canonical snapd. The abstraction rules located in /etc/apparmor.d/abstractions/nss-systemd (inherited via ) inadvertently permit strictly confined snap applications, which lack the privileged account-control interface, to interact directly with the io.systemd.Multiplexer and io.systemd.NameServiceSwitch UNIX domain sockets under /run/systemd/userdb/.
On systems where the systemd-userdbd service is installed and operational, the service fails to distinguish between an unconfined root user on the host system and a restricted root user running within a snap application's sandbox (such as a daemon or configuration hook). Because systemd-userdbd returns "complete" user records—including sensitive hashed user passwords from /etc/shadow—when queried by a process running as root, a compromised or malicious strictly confined snap executing code as root can successfully query the Varlink interface to retrieve all system password hashes, bypassing intended snap sandbox restrictions. This issue is mitigated by the fact that systemd-userdbd is not installed by default on standard Ubuntu deployments.

Comment 1 Aoife Moloney 2026-08-17 15:40:01 UTC

This bug appears to have been reported against 'rawhide' during the Fedora Linux 45 development cycle.
Changing version to 45.