AppArmor Bypass in Canonical snapd via nss-systemd Abstraction
CVE-2024-5300 Published on July 21, 2026

AppArmor Base Profile Misconfiguration in snapd Permits Confined Snaps Unauthorized Access to Hashed Passwords via systemd-userdbd
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 recordsincluding sensitive hashed user passwords from /etc/shadowwhen 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.

NVD

Vulnerability Analysis

CVE-2024-5300 is exploitable with local system access, and requires small amount of user privileges. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality, with no impact on integrity and availability.

Attack Vector:
LOCAL
Attack Complexity:
HIGH
Privileges Required:
LOW
User Interaction:
NONE
Scope:
CHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
NONE
Availability Impact:
NONE

Weakness Type

Improper Removal of Sensitive Information Before Storage or Transfer

The product stores, transfers, or shares a resource that contains sensitive information, but it does not properly remove that information before the product makes the resource available to unauthorized actors.