📖 ~4 min read • Source: Ubuntu Security Notice USN-8181-1
Related CVEs: CVE-2022-23457 CVE-2022-24891 CVE-2025-5878
Upstream summary: Jaroslav Lobačevski discovered that ESAPI incorrectly validated directory
paths during path verification. An attacker could possibly use this issue
to bypass directory validation checks, leading to control-flow bypass. This
issue only affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, Ubuntu 20.04 LTS,
and Ubuntu 22.04 LTS. (CVE-2022-23457)
Kevin W. Wall and Sebastian Passaro discovered that ESAPI did not properly
sanitize javascript URLs because of an incorrect regular expression
Table of contents
Symptom & Impact
On Ubuntu 22.04 (jammy) hosts that have libowasp-esapi-java installed, administrators report behaviour consistent with Ubuntu Security Notice USN-8181-1: apt reports pending security updates, services backed by libowasp-esapi-java 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 libowasp-esapi-java sits on the serving path.
Environment & Reproduction
Reproduction targets Ubuntu 22.04 (jammy). Confirm release and installed package:
lsb_release -a
cat /etc/os-release
dpkg -l libowasp-esapi-java | tail -2
apt-cache policy libowasp-esapi-java
uname -r
Trigger the workflow that exposes libowasp-esapi-java — multiple vulnerabilities (3 CVEs) — patch and remediation guide while collecting:
sudo journalctl -u libowasp-esapi-java -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-8181-1. Canonical security maintainers shipped fixes in the corresponding libowasp-esapi-java update for Ubuntu 22.04; running an outdated build leaves the host exposed to the failure modes described in the advisory. Fixes land in the jammy-security pocket of the main archive. Correlate apt history with the journal:
grep -A2 -B2 libowasp-esapi-java /var/log/apt/history.log
zgrep -A2 -B2 libowasp-esapi-java /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 22.04 to capture the current state of libowasp-esapi-java:
dpkg -l libowasp-esapi-java | tail -1 # installed version
dpkg -V libowasp-esapi-java # verify shipped files
sudo apt update && apt list --upgradable 2>/dev/null | grep -i security
systemctl is-active libowasp-esapi-java
sudo ufw status verbose 2>/dev/null | head -20
sudo aa-status 2>/dev/null | head -20
# If libowasp-esapi-java 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 libowasp | head
Step-by-Step Diagnosis
-
List failing services.
systemctl --failed --no-pager -
Tail the journal / syslog for
libowasp-esapi-java.sudo journalctl -u libowasp-esapi-java -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.libowasp-esapi-java or usr.sbin.libowasp-esapi-java — inspect first sudo aa-complain /etc/apparmor.d/usr.bin.libowasp-esapi-java 2>/dev/null || true -
Verify
libowasp-esapi-javaintegrity and reinstall if anything is altered.sudo dpkg -V libowasp-esapi-java sudo debsums -c libowasp-esapi-java 2>/dev/null sudo apt install --reinstall -y libowasp-esapi-java -
Correlate findings with
/var/log/apt/history.log,/var/log/dpkg.log, and Ubuntu Security Notice USN-8181-1 to pin the change that introduced libowasp-esapi-java — multiple vulnerabilities (3 CVEs) — patch and remediation guide.
Solution – Primary Fix
Apply the corrective apt transaction referenced by Ubuntu Security Notice USN-8181-1, then reload the affected service:
sudo apt update
sudo apt -y install --only-upgrade libowasp-esapi-java
sudo systemctl daemon-reload
# Service name may differ from pkg name; check first:
systemctl list-unit-files | grep -i libowasp | head
sudo systemctl restart libowasp-esapi-java
dpkg -l libowasp-esapi-java | tail -1 # confirm new version
systemctl is-active libowasp-esapi-java
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
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 libowasp-esapi-java apt-mark showhold | grep libowasp-esapi-java # Release the hold later with: sudo apt-mark unhold libowasp-esapi-java -
Pin a known-good version via apt preferences:
# /etc/apt/preferences.d/libowasp-esapi-java.pref Package: libowasp-esapi-java Pin: version <good-version> Pin-Priority: 1001 -
Downgrade to an older version if a regression is suspected:
apt-cache madison libowasp-esapi-java sudo apt install --allow-downgrades -y libowasp-esapi-java=<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.libowasp-esapi-java 2>/dev/null # reproduce the failure sudo journalctl -k | grep apparmor | tail sudo aa-enforce /etc/apparmor.d/usr.bin.libowasp-esapi-java 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 jammy-security libowasp-esapi-java
Verification & Acceptance Criteria
All of these should pass after the fix is applied:
dpkg -l libowasp-esapi-java | tail -1 # expected fixed version
apt list --upgradable 2>/dev/null | grep -i security || echo OK
systemctl is-active libowasp-esapi-java
sudo journalctl -u libowasp-esapi-java --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 libowasp-esapi-java — multiple vulnerabilities (3 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-libowasp-esapi-java
# LVM-on-root:
sudo lvcreate -L 4G -s -n root_pre_patch /dev/<vg>/<root-lv>
To revert:
sudo apt install --allow-downgrades -y libowasp-esapi-java=<old-version>
sudo systemctl daemon-reload
sudo systemctl restart libowasp-esapi-java
# 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-libowasp-esapi-java
Prevention & Hardening
Reduce the chance of this recurring on Ubuntu 22.04 (jammy):
-
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 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
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 libowasp-esapi-java — multiple vulnerabilities (3 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-22-04 tutorials on the Tutorials Hub →
Browse all common problems & solutions on the Tutorials Hub.
References & Further Reading
Primary reference: Ubuntu Security Notice USN-8181-1. Manual pages useful on Ubuntu 22.04:
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/libowasp-esapi-java/ for components implicated in libowasp-esapi-java — multiple vulnerabilities (3 CVEs) — patch and remediation guide.