Ubuntu 24.04 — docker.io — multiple vulnerabilities (8 CVEs) — patch and remediation guide

📖 ~4 min read  •  Source: Ubuntu Security Notice USN-7474-1

Related CVEs: CVE-2023-28840 CVE-2023-28841 CVE-2023-28842 CVE-2024-23651 CVE-2024-23652 CVE-2024-36621 CVE-2024-36623 CVE-2024-41110

Upstream summary: Cory Snider discovered that Docker incorrectly handled networking packet
encapsulation. An attacker could use this issue to inject internet
packets in established connection, possibly causing a denial of service or
bypassing firewall protections. This issue only affected Ubuntu 22.04 LTS,
Ubuntu 20.04 LTS, and Ubuntu 18.04 LTS. (CVE-2023-28840, CVE-2023-28841,
CVE-2023-28842)

Rory McNamara discovered that Docker incorrectly handled cache in the
BuildKit toolkit. An attacker

Table of contents

1. Symptom & Impact
2. Environment & Reproduction
3. Root Cause Analysis
4. Quick Triage
5. Step-by-Step Diagnosis
6. Solution – Primary Fix
7. Solution – Alternative Approaches
8. Verification & Acceptance Criteria
9. Rollback Plan
10. Prevention & Hardening
11. Related Errors & Cross-Refs
12. References & Further Reading

Symptom & Impact

docker.io runs when an image is pulled, unpacked, inspected or a container is started, so a defect here is normally reached through untrusted image content or a registry response rather than inbound traffic to a listening port. On Ubuntu 24.04 that shows up as escapes from the container’s namespaces, files written outside the intended root during buildah or podman build, mount and capability handling that grants more than was requested, and images produced before the update carrying the defect onward to every host that pulls them. docker.io is container tooling — command-line binaries invoked per operation, though a node runtime such as cri-o does run as a unit — so restart steps apply to that runtime and to containers still running the old code, not to docker.io itself.

Environment & Reproduction

Reproduction targets Ubuntu 24.04 (noble). Confirm release and installed package:

lsb_release -a
cat /etc/os-release
dpkg -l docker.io | tail -2
apt-cache policy docker.io
uname -r

Exercise the workload that uses docker.io while collecting:

sudo journalctl -u docker -b --no-pager | tail -200
sudo journalctl -xe --no-pager | tail -200
sudo tail -200 /var/log/apt/history.log
sudo tail -200 /var/log/kern.log | grep -i apparmor

Root Cause Analysis

Root cause is documented in Ubuntu Security Notice USN-7474-1. Canonical security maintainers shipped fixes in the corresponding docker.io update for Ubuntu 24.04; running an outdated build leaves the host exposed to the failure modes described in the advisory. Fixes land in the noble-security pocket of the main archive. Correlate apt history with the journal:

grep -A2 -B2 docker.io /var/log/apt/history.log
zgrep -A2 -B2 docker.io /var/log/apt/history.log.*.gz 2>/dev/null
cat /proc/sys/kernel/tainted   # non-zero = tainted kernel / out-of-tree modules

Quick Triage

Run these on Ubuntu 24.04 to capture the current state of docker.io:

dpkg -l docker.io | tail -1                  # installed version
dpkg -V docker.io                             # verify shipped files
sudo apt update && apt list --upgradable 2>/dev/null | grep -i security
systemctl is-active docker
sudo ufw status verbose 2>/dev/null | head -20
sudo aa-status 2>/dev/null | head -20
# If docker.io ships a service unit (unit/job name often differs from pkg name, e.g.
# bind9→named, apache2→apache2, postgresql-NN→postgresql@NN-main):
systemctl list-unit-files | grep -i docker.io | head

Step-by-Step Diagnosis

1. List failing services.

   systemctl --failed --no-pager

2. Tail the journal / syslog for docker.io.

   sudo journalctl -u docker -f --no-pager
   sudo journalctl -xe -f --no-pager

3. Inspect UFW (Uncomplicated Firewall) state.

   sudo ufw status numbered
   sudo ufw show added
   sudo iptables -L -n -v | head -30

4. Surface AppArmor denials and switch the profile to complain mode if needed.

   sudo journalctl -k 2>/dev/null | grep -i 'apparmor="DENIED"' | tail -30
   sudo aa-status
   # /etc/apparmor.d/usr.bin.docker.io or usr.sbin.docker.io — inspect first
   sudo aa-complain /etc/apparmor.d/usr.bin.docker.io 2>/dev/null || true

5. Verify docker.io integrity and reinstall if anything is altered.

   sudo dpkg -V docker.io
   sudo debsums -c docker.io 2>/dev/null
   sudo apt install --reinstall -y docker.io

6. Correlate findings with /var/log/apt/history.log, /var/log/dpkg.log, and Ubuntu Security Notice USN-7474-1 to pin the change that introduced the regression.

Solution – Primary Fix

Apply the corrective apt transaction referenced by Ubuntu Security Notice USN-7474-1, then reload the affected service:

sudo apt update
sudo apt -y install --only-upgrade docker.io
sudo systemctl daemon-reload
# Service name may differ from pkg name; check first:
systemctl list-unit-files | grep -i docker.io | head
sudo systemctl restart docker
dpkg -l docker.io | tail -1            # confirm new version
systemctl is-active docker

For kernel / glibc / systemd / openssl advisories a reboot (or Livepatch) is required:

sudo apt install -y needrestart
sudo needrestart -r l       # list units that need restart
sudo systemctl reboot       # or: sudo shutdown -r now
# Livepatch (Ubuntu Pro) avoids reboot for many kernel CVEs:
sudo canonical-livepatch status
sudo canonical-livepatch refresh

Solution – Alternative Approaches

If the primary upgrade is not viable, pick from these:

• Hold the package so apt cannot upgrade it:

  sudo apt-mark hold docker.io
  apt-mark showhold | grep docker.io
  # Release the hold later with:
  sudo apt-mark unhold docker.io

• Pin a known-good version via apt preferences:

  # /etc/apt/preferences.d/docker.io.pref
  Package: docker.io
  Pin: version <good-version>
  Pin-Priority: 1001

• Downgrade to an older version if a regression is suspected:

  apt-cache madison docker.io
  sudo apt install --allow-downgrades -y docker.io=<older-version>

• Investigate AppArmor blocking the new binary; switch to complain briefly, capture denials, then re-enforce:

  sudo aa-complain /etc/apparmor.d/usr.bin.docker.io 2>/dev/null
  # reproduce the failure
  sudo journalctl -k | grep apparmor | tail
  sudo aa-enforce /etc/apparmor.d/usr.bin.docker.io 2>/dev/null

• Apply Canonical Livepatch (Ubuntu Pro) to land kernel fixes without reboot:

  sudo canonical-livepatch status
  sudo canonical-livepatch refresh

• Take only the security pocket update and defer the full point-release upgrade:

  sudo apt -y install --only-upgrade -t noble-security docker.io

Verification & Acceptance Criteria

All of these should pass after the fix is applied:

dpkg -l docker.io | tail -1                                  # expected fixed version
apt list --upgradable 2>/dev/null | grep -i security || echo OK
systemctl is-active docker
sudo journalctl -u docker --since "5 minutes ago" --no-pager | grep -iE "error|fail" || echo OK
sudo ufw status numbered | head
sudo aa-status 2>/dev/null | head -5

The conditions described in the advisory must no longer be reported for docker.io across two consecutive runs.

Rollback Plan

Capture state before any change:

apt list --installed 2>/dev/null > /root/apt-pre.txt
dpkg --get-selections > /root/dpkg-pre.txt
# ZFS-on-root (Ubuntu 20.04+ default installer option):
sudo zfs snapshot rpool/ROOT/ubuntu@pre-docker-io
# LVM-on-root:
sudo lvcreate -L 4G -s -n root_pre_patch /dev/<vg>/<root-lv>

To revert:

sudo apt install --allow-downgrades -y docker.io=<old-version>
sudo systemctl daemon-reload
sudo systemctl restart docker
# Kernel rollback: pick the prior kernel from the GRUB menu, then:
sudo systemctl reboot
# ZFS rollback (rolls the whole root dataset):
sudo zfs rollback -r rpool/ROOT/ubuntu@pre-docker-io

Prevention & Hardening

Reduce the chance of this recurring on Ubuntu 24.04 (noble):

• Enable scheduled security updates via unattended-upgrades:

  sudo apt install -y unattended-upgrades update-notifier-common
  sudo dpkg-reconfigure -plow unattended-upgrades
  # /etc/apt/apt.conf.d/50unattended-upgrades:
  Unattended-Upgrade::Allowed-Origins { "${distro_id}:${distro_codename}-security"; };

• Install needrestart so services restart automatically after library upgrades:

  sudo apt install -y needrestart
  # /etc/needrestart/needrestart.conf -> $nrconf{restart} = 'a';

• Attach Ubuntu Pro to enable Livepatch and extended security coverage:

  sudo pro attach <token>
  sudo pro enable livepatch

• Subscribe to ubuntu-security-announce and watch ubuntu.com/security/cves.

• Monitor file integrity with debsums and AIDE:

  sudo apt install -y debsums aide
  sudo debsums -ca
  sudo aideinit && sudo mv /var/lib/aide/aide.db.new /var/lib/aide/aide.db
  sudo aide --check

• For estate-wide patching, manage with Canonical Landscape:

  sudo apt install -y landscape-client
  sudo landscape-config

• Keep AppArmor profiles in enforce mode and apply CIS Ubuntu Linux Benchmark hardening.

Related Errors & Cross-Refs

Issues that commonly surface alongside a docker.io update: apt lock contention, broken dpkg state, systemd ordering cycles, AppArmor denials, and UFW rule drift. Useful triage:

sudo dpkg --configure -a
sudo apt --fix-broken install
systemd-analyze critical-chain
sudo journalctl -k 2>/dev/null | grep -i apparmor | tail
cat /proc/sys/kernel/tainted

View all ubuntu-24-04 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Primary reference: Ubuntu Security Notice USN-7474-1. Manual pages useful on Ubuntu 24.04:

man apt
man apt-get
man apt-mark
man dpkg
man systemctl
man journalctl
man ufw
man apparmor
man aa-status
man unattended-upgrades
man canonical-livepatch
man pro

Other resources: Ubuntu Security Notices, Ubuntu CVE Tracker, Ubuntu upgrade notes, and per-package notes in /usr/share/doc/docker.io/ for components implicated in this advisory.