Ubuntu 22.04 — dogtag-pki — multiple vulnerabilities (3 CVEs) — patch and remediation guide

📖 ~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

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 22.04 hosts running dogtag-pki, the vulnerable code is started by something else – a web or application server, or an on-demand supervisor such as inetd, xinetd or a systemd socket unit – rather than by a service of its own. Patching replaces the files on disk immediately, but a long-running parent that has already loaded them (PHP-FPM workers, an application server, a persistent worker pool) keeps serving the old code until it is recycled. Connection-per-process supervisors pick the fix up on the next connection, so the exposure window differs sharply between the two and is worth confirming rather than assuming. dogtag-pki is started by a hosting server or an on-demand supervisor rather than by a unit of its own, so restart whatever launches it – not dogtag-pki.

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

Exercise the workload that uses dogtag-pki while collecting:

needrestart -b -r l  # (pkg: needrestart) run as root; machine-readable. NEEDRESTART-SVC = units still mapping deleted libs, NEEDRESTART-SESS = login sessions, NEEDRESTART-KSTA = kernel state. -r l never restarts anything
needrestart -v -l -r l  # human-readable, libraries only (-l); names each PID and the obsolete file it still maps
checkrestart -v  # (pkg: debian-goodies) older alternative; add -p to report only deleted files owned by a dpkg package, -m for machine-readable
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 daemon-reload  # only if the upgrade shipped changed unit files
systemctl daemon-reexec  # REQUIRED after a systemd / libsystemd upgrade: re-execs PID 1 against the new library without rebooting (needrestart flags this as 'systemd-manager')
needrestart -r i  # (pkg: needrestart) interactive: prompts per service. The safe default on a production box
needrestart -r a  # non-interactive: restarts EVERY flagged unit. Maintenance window only -- it will bounce databases and web servers without asking
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):
dpkg-query -L dogtag-pki 2>/dev/null | grep -E '^/etc/init\.d/[^/]+$'  # legacy SysV init script; its basename is the service name for 'service <name> restart' on non-systemd hosts
systemctl list-unit-files --no-pager --type=service,socket,timer | grep -iF -- 'dogtag-pki'  # fuzzy name match; -F is required because package names contain regex metacharacters ('+' in libstdc++6/g++-13 makes -E fail to match at all)

Step-by-Step Diagnosis

1. List failing services.

   systemctl --failed --no-pager

2. Tail the journal / syslog for dogtag-pki.

   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.dogtag-pki or usr.sbin.dogtag-pki — inspect first
   sudo aa-complain /etc/apparmor.d/usr.bin.dogtag-pki 2>/dev/null || true

5. Verify dogtag-pki integrity 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

6. 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 the regression.

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:
dpkg -l dogtag-pki | tail -1            # confirm new version

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 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
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 dogtag-pki 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
# 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 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 dogtag-pki 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-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 this advisory.