📖 ~4 min read • Source: Ubuntu Security Notice USN-4813-1
Related CVEs: CVE-2018-11307 CVE-2018-12022 CVE-2018-12023 CVE-2018-14718 CVE-2018-14719 CVE-2018-14720 CVE-2018-14721 CVE-2018-19360 +12 more
Upstream summary: It was discovered that Jackson Databind incorrectly handled
deserialization. An attacker could possibly use this issue to obtain
sensitive information. (CVE-2018-11307, CVE-2019-12086, CVE-2019-12814)
It was discovered that Jackson Databind incorrectly handled
deserialization. An attacker could possibly use this issue to execute
arbitrary code or other unspecified impact. (CVE-2018-12022,
CVE-2018-12023, CVE-2018-14718, CVE-2018-14719, CVE-2018-19360,
CVE-2018-19361, CVE-201
Table of contents
Symptom & Impact
On Ubuntu 16.04 (xenial) hosts that have jackson-databind installed, administrators report behaviour consistent with Ubuntu Security Notice USN-4813-1: apt reports pending security updates, services backed by jackson-databind fail or restart unexpectedly, AppArmor denials appear in the kernel log, and — for security-rated advisories — the host is exposed to the vulnerability set above. Impact ranges from a single service-restart loop to wider availability incidents whenever jackson-databind sits on the serving path.
Environment & Reproduction
Reproduction targets Ubuntu 16.04 (xenial). Confirm release and installed package:
lsb_release -a
cat /etc/os-release
dpkg -l jackson-databind | tail -2
apt-cache policy jackson-databind
uname -r
Trigger the workflow that exposes jackson-databind — multiple vulnerabilities (20 CVEs) — patch and remediation guide while collecting:
sudo journalctl -u jackson-databind -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-4813-1. Canonical security maintainers shipped fixes in the corresponding jackson-databind update for Ubuntu 16.04; running an outdated build leaves the host exposed to the failure modes described in the advisory. On this release the fix typically arrives via the Ubuntu Pro ESM (esm-infra / esm-apps) channels rather than the standard archive. Correlate apt history with the journal:
grep -A2 -B2 jackson-databind /var/log/apt/history.log
zgrep -A2 -B2 jackson-databind /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 16.04 to capture the current state of jackson-databind:
dpkg -l jackson-databind | tail -1 # installed version
dpkg -V jackson-databind # verify shipped files
sudo apt update && apt list --upgradable 2>/dev/null | grep -i security
systemctl is-active jackson-databind
sudo ufw status verbose 2>/dev/null | head -20
sudo aa-status 2>/dev/null | head -20
# If jackson-databind 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 jackson | head
On xenial the standard archive no longer ships security fixes. Verify Ubuntu Pro ESM coverage:
# `pro` CLI not available on this release; check the older `ubuntu-advantage-tools`:
sudo ua status --format=json 2>/dev/null | head
apt-cache policy | grep -i esm
Step-by-Step Diagnosis
-
List failing services.
systemctl --failed --no-pager -
Tail the journal / syslog for
jackson-databind.sudo journalctl -u jackson-databind -f --no-pager sudo journalctl -xe -f --no-pager -
Inspect UFW (Uncomplicated Firewall) state.
sudo ufw status numbered sudo ufw show added sudo iptables -L -n -v | head -30 -
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.jackson-databind or usr.sbin.jackson-databind — inspect first sudo aa-complain /etc/apparmor.d/usr.bin.jackson-databind 2>/dev/null || true -
Verify
jackson-databindintegrity and reinstall if anything is altered.sudo dpkg -V jackson-databind sudo debsums -c jackson-databind 2>/dev/null sudo apt install --reinstall -y jackson-databind -
Correlate findings with
/var/log/apt/history.log,/var/log/dpkg.log, and Ubuntu Security Notice USN-4813-1 to pin the change that introduced jackson-databind — multiple vulnerabilities (20 CVEs) — patch and remediation guide.
Solution – Primary Fix
Apply the corrective apt transaction referenced by Ubuntu Security Notice USN-4813-1, then reload the affected service:
sudo apt update
sudo apt -y install --only-upgrade jackson-databind
sudo systemctl daemon-reload
# Service name may differ from pkg name; check first:
systemctl list-unit-files | grep -i jackson | head
sudo systemctl restart jackson-databind
dpkg -l jackson-databind | tail -1 # confirm new version
systemctl is-active jackson-databind
On xenial the standard archive is past EoL for security; enable Ubuntu Pro ESM to receive the fix:
# Older releases use the `ua` command:
sudo ua attach <token>
sudo ua enable esm-infra
sudo ua enable esm-apps
sudo apt update
sudo apt -y install --only-upgrade jackson-databind
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
Need help rolling this patch across an Ubuntu fleet? Our IT Solutions & Services team manages Ubuntu patch windows with Landscape and Ubuntu Pro integration. Get in touch for a free consultation.
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 jackson-databind apt-mark showhold | grep jackson-databind # Release the hold later with: sudo apt-mark unhold jackson-databind -
Pin a known-good version via apt preferences:
# /etc/apt/preferences.d/jackson-databind.pref Package: jackson-databind Pin: version <good-version> Pin-Priority: 1001 -
Downgrade to an older version if a regression is suspected:
apt-cache madison jackson-databind sudo apt install --allow-downgrades -y jackson-databind=<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.jackson-databind 2>/dev/null # reproduce the failure sudo journalctl -k | grep apparmor | tail sudo aa-enforce /etc/apparmor.d/usr.bin.jackson-databind 2>/dev/null -
Take only the security pocket update and defer the full point-release upgrade:
sudo apt -y install --only-upgrade -t xenial-security jackson-databind
Verification & Acceptance Criteria
All of these should pass after the fix is applied:
dpkg -l jackson-databind | tail -1 # expected fixed version
apt list --upgradable 2>/dev/null | grep -i security || echo OK
systemctl is-active jackson-databind
sudo journalctl -u jackson-databind --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 original reproduction for jackson-databind — multiple vulnerabilities (20 CVEs) — patch and remediation guide must not trigger 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-jackson-databind
# LVM-on-root:
sudo lvcreate -L 4G -s -n root_pre_patch /dev/<vg>/<root-lv>
To revert:
sudo apt install --allow-downgrades -y jackson-databind=<old-version>
sudo systemctl daemon-reload
sudo systemctl restart jackson-databind
# 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-jackson-databind
Prevention & Hardening
Reduce the chance of this recurring on Ubuntu 16.04 (xenial):
-
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
needrestartso services restart automatically after library upgrades:sudo apt install -y needrestart # /etc/needrestart/needrestart.conf -> $nrconf{restart} = 'a'; -
Attach Ubuntu Pro for ESM (mandatory on this past-EoL release) and Livepatch where supported:
sudo ua attach <token> sudo ua enable esm-infra sudo ua enable esm-apps -
Subscribe to ubuntu-security-announce and watch ubuntu.com/security/cves.
-
Monitor file integrity with
debsumsand 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 jackson-databind — multiple vulnerabilities (20 CVEs) — patch and remediation guide: 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-16-04 tutorials on the Tutorials Hub →
Browse all common problems & solutions on the Tutorials Hub.
References & Further Reading
Primary reference: Ubuntu Security Notice USN-4813-1. Manual pages useful on Ubuntu 16.04:
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 ua
Other resources: Ubuntu Security Notices, Ubuntu CVE Tracker, Ubuntu upgrade notes, and per-package notes in /usr/share/doc/jackson-databind/ for components implicated in jackson-databind — multiple vulnerabilities (20 CVEs) — patch and remediation guide.