Medium [CVE-2024-5300] Canonical snapd: Information disclosure of system password hashes via AppArmor bypass
This medium-severity Red Hat Linux advisory covers CVE-2024-5300 affecting Red Hat Hardened Images.
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Summary
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. The base AppArmor security profile configuration in snapd inadvertently allows strictly confined snap applications to bypass intended sandbox restrictions.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.
Official advisory · high-confidence parse· fetched 12 days ago·verify at source
- systemd-main-261-2.hum1
- RHSA-2026:29009
Official advisory · high-confidence parse· fetched 12 days ago·verify at source
Mitigation
Upgrade to a fixed release: systemd-main-261-2.hum1, RHSA-2026:29009. That is the remediation for this advisory.
The vendor advisory may list additional interim mitigations or workarounds not captured here — review it before change work.
Official advisory · high-confidence parse· fetched 12 days ago·verify at source
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