📖 ~4 min read • Source: Ubuntu Security Notice USN-6969-1
Related CVEs: CVE-2024-25641 CVE-2024-29894 CVE-2024-31443 CVE-2024-31444 CVE-2024-31445 CVE-2024-31458 CVE-2024-31459 CVE-2024-31460 +1 more
Upstream summary: It was discovered that Cacti did not properly apply checks to the "Package
Import" feature. An attacker could possibly use this issue to perform
arbitrary code execution. This issue only affected Ubuntu 24.04 LTS, Ubuntu
22.04 LTS, Ubuntu 20.04 LTS and Ubuntu 18.04 LTS. (CVE-2024-25641)
It was discovered that Cacti did not properly sanitize values when using
javascript based API. A remote attacker could possibly use this issue to
inject arbitrary javascript code resulting in
Table of contents
Symptom & Impact
On Ubuntu 24.04 hosts running cacti, 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. cacti 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 cacti.
Environment & Reproduction
Reproduction targets Ubuntu 24.04 (noble). Confirm release and installed package:
lsb_release -a
cat /etc/os-release
dpkg -l cacti | tail -2
apt-cache policy cacti
uname -r
Exercise the workload that uses cacti 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-6969-1. Canonical security maintainers shipped fixes in the corresponding cacti update for Ubuntu 24.04; running an outdated build leaves the host exposed to the failure modes described in the advisory. Fixes land in the noble-security pocket of the main archive. Correlate apt history with the journal:
grep -A2 -B2 cacti /var/log/apt/history.log
zgrep -A2 -B2 cacti /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 24.04 to capture the current state of cacti:
dpkg -l cacti | tail -1 # installed version
dpkg -V cacti # 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 cacti 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 cacti 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 -- 'cacti' # 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
-
List failing services.
systemctl --failed --no-pager -
Tail the journal / syslog for
cacti.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.cacti or usr.sbin.cacti — inspect first sudo aa-complain /etc/apparmor.d/usr.bin.cacti 2>/dev/null || true -
Verify
cactiintegrity and reinstall if anything is altered.sudo dpkg -V cacti sudo debsums -c cacti 2>/dev/null sudo apt install --reinstall -y cacti -
Correlate findings with
/var/log/apt/history.log,/var/log/dpkg.log, and Ubuntu Security Notice USN-6969-1 to pin the change that introduced the regression.
Solution – Primary Fix
Apply the corrective apt transaction referenced by Ubuntu Security Notice USN-6969-1, then reload the affected service:
sudo apt update
sudo apt -y install --only-upgrade cacti
sudo systemctl daemon-reload
# Service name may differ from pkg name; check first:
dpkg -l cacti | 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
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 cacti apt-mark showhold | grep cacti # Release the hold later with: sudo apt-mark unhold cacti -
Pin a known-good version via apt preferences:
# /etc/apt/preferences.d/cacti.pref Package: cacti Pin: version <good-version> Pin-Priority: 1001 -
Downgrade to an older version if a regression is suspected:
apt-cache madison cacti sudo apt install --allow-downgrades -y cacti=<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.cacti 2>/dev/null # reproduce the failure sudo journalctl -k | grep apparmor | tail sudo aa-enforce /etc/apparmor.d/usr.bin.cacti 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 noble-security cacti
Verification & Acceptance Criteria
All of these should pass after the fix is applied:
dpkg -l cacti | 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 cacti 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-cacti
# LVM-on-root:
sudo lvcreate -L 4G -s -n root_pre_patch /dev/<vg>/<root-lv>
To revert:
sudo apt install --allow-downgrades -y cacti=<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-cacti
Prevention & Hardening
Reduce the chance of this recurring on Ubuntu 24.04 (noble):
-
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 a cacti 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-24-04 tutorials on the Tutorials Hub →
Browse all common problems & solutions on the Tutorials Hub.
References & Further Reading
Primary reference: Ubuntu Security Notice USN-6969-1. Manual pages useful on Ubuntu 24.04:
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/cacti/ for components implicated in this advisory.