📖 ~4 min read • Source: Ubuntu Security Notice USN-7146-1
Related CVEs: CVE-2017-7537 CVE-2020-25715 CVE-2022-2414
Upstream summary: Christina Fu discovered that Dogtag PKI accidentally enabled a mock
authentication plugin by default. An attacker could potentially use
this flaw to bypass the regular authentication process and trick the
CA server into issuing certificates. This issue only affected Ubuntu
16.04 LTS. (CVE-2017-7537)
It was discovered that Dogtag PKI did not properly sanitize user
input. An attacker could possibly use this issue to perform cross site
scripting and obtain sensitive information
Table of contents
Symptom & Impact
On Ubuntu 22.04 (jammy) hosts that have dogtag-pki installed, administrators report behaviour consistent with Ubuntu Security Notice USN-7146-1: apt reports pending security updates, services backed by dogtag-pki 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 dogtag-pki 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 dogtag-pki | tail -2
apt-cache policy dogtag-pki
uname -r
Trigger the workflow that exposes dogtag-pki — multiple vulnerabilities (3 CVEs) — patch and remediation guide while collecting:
sudo journalctl -u dogtag-pki -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-7146-1. Canonical security maintainers shipped fixes in the corresponding dogtag-pki update for Ubuntu 22.04; running an outdated build leaves the host exposed to the failure modes described in the advisory.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 dogtag-pki /var/log/apt/history.log
zgrep -A2 -B2 dogtag-pki /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 dogtag-pki:
dpkg -l dogtag-pki | tail -1 # installed version
dpkg -V dogtag-pki # verify shipped files
sudo apt update && apt list --upgradable 2>/dev/null | grep -i security
systemctl is-active dogtag-pki
sudo ufw status verbose 2>/dev/null | head -20
sudo aa-status 2>/dev/null | head -20
# If dogtag-pki 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 dogtag | head
Step-by-Step Diagnosis
-
List failing services.
systemctl --failed --no-pager -
Tail the journal / syslog for
dogtag-pki.sudo journalctl -u dogtag-pki -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.dogtag-pki or usr.sbin.dogtag-pki — inspect first sudo aa-complain /etc/apparmor.d/usr.bin.dogtag-pki 2>/dev/null || true -
Verify
dogtag-pkiintegrity and reinstall if anything is altered.sudo dpkg -V dogtag-pki sudo debsums -c dogtag-pki 2>/dev/null sudo apt install --reinstall -y dogtag-pki -
Correlate findings with
/var/log/apt/history.log,/var/log/dpkg.log, and Ubuntu Security Notice USN-7146-1 to pin the change that introduced dogtag-pki — multiple vulnerabilities (3 CVEs) — patch and remediation guide.
Solution – Primary Fix
Apply the corrective apt transaction referenced by Ubuntu Security Notice USN-7146-1, then reload the affected service:
sudo apt update
sudo apt -y install --only-upgrade dogtag-pki
sudo systemctl daemon-reload
# Service name may differ from pkg name; check first:
systemctl list-unit-files | grep -i dogtag | head
sudo systemctl restart dogtag-pki
dpkg -l dogtag-pki | tail -1 # confirm new version
systemctl is-active dogtag-pki
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 dogtag-pki apt-mark showhold | grep dogtag-pki # Release the hold later with: sudo apt-mark unhold dogtag-pki -
Pin a known-good version via apt preferences:
# /etc/apt/preferences.d/dogtag-pki.pref Package: dogtag-pki Pin: version <good-version> Pin-Priority: 1001 -
Downgrade to an older version if a regression is suspected:
apt-cache madison dogtag-pki sudo apt install --allow-downgrades -y dogtag-pki=<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.dogtag-pki 2>/dev/null # reproduce the failure sudo journalctl -k | grep apparmor | tail sudo aa-enforce /etc/apparmor.d/usr.bin.dogtag-pki 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 dogtag-pki
Verification & Acceptance Criteria
All of these should pass after the fix is applied:
dpkg -l dogtag-pki | tail -1 # expected fixed version
apt list --upgradable 2>/dev/null | grep -i security || echo OK
systemctl is-active dogtag-pki
sudo journalctl -u dogtag-pki --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 dogtag-pki — 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-dogtag-pki
# LVM-on-root:
sudo lvcreate -L 4G -s -n root_pre_patch /dev/<vg>/<root-lv>
To revert:
sudo apt install --allow-downgrades -y dogtag-pki=<old-version>
sudo systemctl daemon-reload
sudo systemctl restart dogtag-pki
# 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-dogtag-pki
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 dogtag-pki — 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-7146-1. 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/dogtag-pki/ for components implicated in dogtag-pki — multiple vulnerabilities (3 CVEs) — patch and remediation guide.