Ubuntu 16.04 — shiro — multiple vulnerabilities (5 CVEs) — patch and remediation guide

📖 ~4 min read  •  Source: Ubuntu Security Notice USN-7147-1

Related CVEs: CVE-2016-6802 CVE-2023-34478 CVE-2023-46749 CVE-2023-46750 CVE-2016-4437

Upstream summary: It was discovered that Apache Shiro incorrectly handled path traversal when
used with other web frameworks or path rewriting. An attacker could
possibly use this issue to obtain sensitive information or administrative
privileges. This update provides the corresponding fix for Ubuntu 24.04 LTS
and Ubuntu 24.10. (CVE-2023-34478, CVE-2023-46749)

It was discovered that Apache Shiro incorrectly handled web redirects when
used together with the form authentication method. An attac

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

On Ubuntu 16.04 hosts running shiro, administrators report behaviour consistent with Ubuntu Security Notice USN-7147-1: apt refusing to install or restart affected services, AppArmor denials in journalctl -k, and — for security-rated advisories — exposure to the vulnerability set above. In production estates the visible impact ranges from a single service restart to wider availability incidents whenever shiro sits on the serving path.

Environment & Reproduction

Reproduction targets Ubuntu 16.04. Confirm release with lsb_release -a and cat /etc/os-release, and the currently installed package with dpkg -l shiro and apt-cache policy shiro. Capture system state with sudo ubuntu-bug shiro or sudo apport-collect for an evidence bundle. Trigger the workflow that exposes shiro — multiple vulnerabilities (5 CVEs) — patch and remediation guide while collecting journalctl -b, /var/log/apt/history.log, and dpkg -l output.

Root Cause Analysis

Root cause is documented in Ubuntu Security Notice USN-7147-1. Canonical security maintainers shipped fixes in the corresponding shiro update for Ubuntu 16.04; running an outdated build leaves the host exposed to the failure modes described in the advisory. Correlate journalctl --since timestamps with apt history (/var/log/apt/history.log) and any AppArmor denials in /var/log/syslog to isolate the originating change.

Quick Triage

Quick triage: run systemctl status shiro, journalctl -u shiro -n 200, sudo apt update && apt list --upgradable, sudo ufw status verbose, and sudo aa-status. If AppArmor is in enforce mode, capture journalctl -k | grep apparmor to surface denials linked to shiro — multiple vulnerabilities (5 CVEs) — patch and remediation guide.

Step-by-Step Diagnosis

1) Confirm symptom with systemctl --failed. 2) Inspect logs: journalctl -xe and journalctl -u shiro. 3) Validate firewall: sudo ufw status numbered. 4) Check AppArmor: sudo aa-status and journalctl -k | grep apparmor. 5) Verify package integrity: dpkg -V shiro and sudo apt install --reinstall shiro. 6) Correlate findings with apt list --installed shiro, /var/log/apt/history.log, and Ubuntu Security Notice USN-7147-1 to pin the change that introduced shiro — multiple vulnerabilities (5 CVEs) — patch and remediation guide.

Solution – Primary Fix

Primary fix for shiro — multiple vulnerabilities (5 CVEs) — patch and remediation guide: apply the corrective apt transaction described in Ubuntu Security Notice USN-7147-1, reload the affected systemd unit, and reconcile UFW / AppArmor state. Typical commands: sudo apt update, sudo apt -y install --only-upgrade shiro or sudo unattended-upgrade -v, sudo systemctl daemon-reload, sudo systemctl restart shiro, then dpkg -l shiro to validate the new build is installed. For kernel advisories add sudo reboot or apply Ubuntu Livepatch (canonical-livepatch status) where covered by your Ubuntu Pro subscription.

Solution – Alternative Approaches

Alternatives include pinning a known-good version via /etc/apt/preferences.d/shiro.pref with apt-mark hold shiro, rolling back with sudo apt install shiro=<old-version>, rotating UFW rules with sudo ufw reload, switching AppArmor profiles to complain mode (sudo aa-complain /etc/apparmor.d/usr.bin.shiro) to confirm policy is the cause before authoring a custom profile, or applying Canonical Livepatch fixes via canonical-livepatch refresh where Ubuntu Pro is subscribed.

Verification & Acceptance Criteria

Acceptance: dpkg -l shiro shows the expected fixed version, systemctl is-active shiro returns active, journalctl -u shiro --since "5 minutes ago" shows no errors, apt list --upgradable no longer lists the advisory, sudo ufw status shows required services, sudo aa-status reports the intended profile mode, and the original reproduction steps for shiro — multiple vulnerabilities (5 CVEs) — patch and remediation guide no longer trigger the failure across two consecutive runs.

Rollback Plan

Capture state with apt list --installed > /root/apt-pre.txt, dpkg --get-selections > /root/dpkg-pre.txt, and where available sudo zfs snapshot rpool/ROOT/ubuntu@pre-shiro on ZFS-on-root installs. To revert, run sudo apt install --allow-downgrades shiro=<old-version> and reload systemctl daemon-reload. Remove custom AppArmor profiles with sudo apparmor_parser -R. Reboot if the kernel or initramfs changed and re-verify symptoms.

Prevention & Hardening

Prevent recurrence by enabling unattended-upgrades with Unattended-Upgrade::Allowed-Origins tuned to ${distro_id}:${distro_codename}-security, subscribing to the ubuntu-security-announce mailing list, mirroring through Landscape / a local apt-mirror for controlled rollouts, version-locking sensitive packages, and monitoring file integrity with aide --check. Apply CIS Ubuntu hardening, keep AppArmor in enforce, and enable Canonical Livepatch under Ubuntu Pro so kernel advisories can be remediated without reboot.

Related Errors & Cross-Refs

Related issues that commonly surface alongside shiro — multiple vulnerabilities (5 CVEs) — patch and remediation guide: apt lock contention (dpkg --configure -a), systemd unit ordering cycles, AppArmor denials in journalctl -k, UFW zone drift, and kernel taint flags in cat /proc/sys/kernel/tainted. See sibling common-problem articles in this Ubuntu 16.04 series for adjacent failure modes.

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-7147-1. Supporting docs: Ubuntu Server Guide, man apt, man systemctl, man ufw, man aa-status, man apparmor, man journalctl, the Ubuntu CVE Tracker at ubuntu.com/security/cves, and Canonical Livepatch docs. Review /usr/share/doc/shiro/ for component-level notes implicated in shiro — multiple vulnerabilities (5 CVEs) — patch and remediation guide.