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Fencer Vulns
medium 5.6

CVE-2024-5300 json

AppArmor Base Profile Misconfiguration in snapd Permits Confined Snaps Unauthorized Access to Hashed Passwords via systemd-userdbd

published 2026-07-21 3 mo ago modified 2026-07-22 3 mo ago also EUVD-2024-55693

cvss
5.6
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 2%
public exploits
0
none known

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.

Patch / fix

  • Canonical Ubuntu 26.04 LTS 2.76+ubuntu26.04.3
  • Canonical Ubuntu 24.04 LTS 2.76+ubuntu24.04.1
  • Canonical Ubuntu 22.04 LTS 2.76+ubuntu22.04.1
  • Canonical Ubuntu 20.04 LTS 2.67.1+20.04ubuntu1~esm2
  • Canonical Ubuntu 18.04 LTS 2.61.4ubuntu0.18.04.1+esm3
  • Canonical Ubuntu 16.04 LTS 2.61.4ubuntu0.16.04.1+esm3
  • snapd Debian 14 2.76.3-1

debian advisories DEBIAN-CVE-2024-5300

  • snapd Ubuntu 22.04 LTS 2.76+ubuntu22.04.1
  • snapd Ubuntu 24.04 LTS 2.76+ubuntu24.04.1
  • snapd Ubuntu 26.04 LTS 2.76+ubuntu26.04.3
  • snapd Ubuntu Pro 16.04 LTS 2.61.4ubuntu0.16.04.1+esm4
  • snapd Ubuntu Pro 18.04 LTS 2.61.4ubuntu0.18.04.1+esm4
  • snapd Ubuntu Pro 20.04 LTS 2.67.1+20.04ubuntu1~esm3

ubuntu advisories UBUNTU-CVE-2024-5300

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • systemd hummingbird 1 261-2.hum1
  • systemd-pam hummingbird 1 261-2.hum1
  • systemd-libs hummingbird 1 261-2.hum1
  • systemd-udev hummingbird 1 261-2.hum1
  • systemd-tests hummingbird 1 261-2.hum1
  • systemd-ukify hummingbird 1 261-2.hum1
  • systemd-shared hummingbird 1 261-2.hum1
  • systemd-networkd hummingbird 1 261-2.hum1

red hat advisories RHSA-2026:29009

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2024-5300 updated cvss 5.6

snapd: systemd: Canonical snapd: Information disclosure of system password hashes via AppArmor bypass

  • Red Hat Hardened Images systemd 261-2.hum1, systemd-networkd-defaults 261-2.hum1
    fixed: vendor fix RHSA-2026:29009

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
3 mo ago

Exploit prediction

0.13% chance of exploitation in the next 30 days, higher than 2% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.6 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N

Affected products

  • Canonical Ubuntu 26.04 LTS
  • Canonical Ubuntu 24.04 LTS
  • Canonical Ubuntu 22.04 LTS
  • Canonical Ubuntu 20.04 LTS
  • Canonical Ubuntu 18.04 LTS
  • Canonical Ubuntu 16.04 LTS

Classification

Weakness
  • CWE-212 Improper Removal of Sensitive Information Before Storage or Transfer

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.