📖 ~4 min read • Source: Debian Security Tracker
Related CVEs: CVE-2020-7746
Upstream summary: This affects the package chart.js before 2.9.4. The options parameter is not properly sanitized when it is processed. When the options are processed, the existing options (or the defaults options) are deeply merged with provided options. However, during this operation, the keys of the object being set are not checked, leading to a prototype pollution.
Table of contents
Symptom & Impact
On Debian 12 (bookworm) hosts that have node-chart.js installed, administrators observe behaviour consistent with Debian Security Tracker: apt reports pending security updates, services backed by node-chart.js fail or restart unexpectedly, 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 node-chart.js sits on the serving path.
Environment & Reproduction
Reproduction targets Debian 12 (bookworm). Confirm release and installed package:
cat /etc/debian_version
lsb_release -a 2>/dev/null || cat /etc/os-release
dpkg -l node-chart.js | tail -2
apt-cache policy node-chart.js
dpkg-query -W -f='${Status}\n' node-chart.js
Trigger the workflow that exposes node-chart.js — vulnerability — patch and remediation guide while collecting:
sudo journalctl -u node-chart.js -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/dpkg.log
Root Cause Analysis
Root cause is tracked at Debian Security Tracker. The Debian Security Team shipped fixes in the corresponding node-chart.js point release for Debian 12 (suite bookworm-security); running an outdated build leaves the host exposed to the failure modes referenced above. Correlate apt history with the journal:
grep -A2 -B2 node-chart.js /var/log/apt/history.log
zgrep -A2 -B2 node-chart.js /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 Debian 12 to capture the current state of node-chart.js:
dpkg -l node-chart.js | tail -1 # installed version
dpkg -V node-chart.js # verify shipped files
sudo apt update && apt list --upgradable 2>/dev/null | grep -i security
systemctl --failed --no-pager
sudo nft list ruleset 2>/dev/null | head -50
sudo aa-status 2>/dev/null | head -20 # AppArmor profiles
# If node-chart.js ships a systemd unit (unit name may differ from pkg, e.g. bind9→named,
# postgresql-NN→postgresql@NN-main, php-fpm→php<ver>-fpm):
systemctl list-unit-files | grep -i node | head
Step-by-Step Diagnosis
-
List failed systemd units.
systemctl --failed --no-pager -
Tail the journal for
node-chart.jsand the system bus.sudo journalctl -u node-chart.js -f --no-pager sudo journalctl -xe -f --no-pager -
Inspect firewall state (this OS defaults to nftables).
sudo nft list ruleset sudo nft list tables -
Verify
node-chart.jsfile integrity and reinstall if anything is altered.sudo dpkg -V node-chart.js sudo debsums -c node-chart.js 2>/dev/null sudo apt install --reinstall -y node-chart.js -
Check AppArmor denials (Debian 11+ default-enabled).
sudo journalctl -k | grep -i 'apparmor="DENIED"' | tail -30 sudo aa-status | grep -i node -
Correlate findings with
/var/log/apt/history.log,/var/log/dpkg.log, and Debian Security Tracker to pin the change that introduced node-chart.js — vulnerability — patch and remediation guide.
Solution – Primary Fix
Apply the corrective apt transaction documented in Debian Security Tracker from the security suite, then reload the affected unit:
sudo apt update
sudo apt -y install --only-upgrade node-chart.js
sudo systemctl daemon-reload
# Unit name may differ from package name; check first:
systemctl list-unit-files | grep -i node | head
sudo systemctl restart node-chart.js
dpkg -l node-chart.js | tail -1 # confirm new version
systemctl is-active node-chart.js 2>/dev/null # confirm running (if a unit exists)
For kernel / glibc / systemd / openssl advisories a reboot is required:
sudo apt install -y needrestart
sudo needrestart -r l # list services that need restart
sudo systemctl reboot # or: sudo shutdown -r now
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Solution – Alternative Approaches
If the primary upgrade is not viable, pick from these:
-
Pin a known-good version via apt preferences:
# /etc/apt/preferences.d/node-chart.js.pref Package: node-chart.js Pin: version <good-version> Pin-Priority: 1001 -
Mark the package on hold so apt cannot upgrade it:
sudo apt-mark hold node-chart.js apt-mark showhold | grep node-chart.js # Release the hold later with: sudo apt-mark unhold node-chart.js -
Downgrade to an older NVR if a regression is suspected:
apt-cache madison node-chart.js sudo apt install --allow-downgrades -y node-chart.js=<older-version> -
Switch firewall backend between iptables-legacy and nftables (Debian 10+):
sudo update-alternatives --config iptables sudo update-alternatives --config ip6tables sudo systemctl restart netfilter-persistent 2>/dev/null -
Take only the security archive update and defer the full point-release upgrade:
# /etc/apt/sources.list.d/bookworm-security-only.list deb http://security.debian.org/debian-security bookworm-security main contrib non-free # then: sudo apt update && sudo apt -y install --only-upgrade -t bookworm-security node-chart.js -
Investigate AppArmor blocking the new binary; switch the profile to complain mode briefly:
sudo aa-complain /etc/apparmor.d/usr.sbin.node-chart.js 2>/dev/null # reproduce, capture denials, then re-enforce: sudo aa-enforce /etc/apparmor.d/usr.sbin.node-chart.js 2>/dev/null
Verification & Acceptance Criteria
All of these should pass after the fix is applied:
dpkg -l node-chart.js | tail -1 # expected fixed version
apt list --upgradable 2>/dev/null | grep -i security || echo OK
systemctl is-active node-chart.js 2>/dev/null # active (if a unit exists)
sudo journalctl -u node-chart.js --since "5 minutes ago" --no-pager # no new errors
sudo nft list ruleset | head
sudo aa-status 2>/dev/null | head -5
The original reproduction for node-chart.js — vulnerability — 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
# LVM snapshot of the root LV (only if root sits on LVM):
sudo lvcreate -L 4G -s -n root_pre_patch /dev/<vg>/<root-lv>
To revert:
sudo apt install --allow-downgrades -y node-chart.js=<old-version>
sudo systemctl daemon-reload
sudo systemctl restart node-chart.js
# If a kernel was rolled back, reboot and select the previous kernel from GRUB:
sudo systemctl reboot
# LVM snapshot merge (offline / on next reboot):
sudo lvconvert --merge /dev/<vg>/root_pre_patch
Prevention & Hardening
Reduce the chance of this recurring on Debian 12:
-
Enable scheduled security updates via
unattended-upgrades:sudo apt install -y unattended-upgrades apt-listchanges sudo dpkg-reconfigure -plow unattended-upgrades # /etc/apt/apt.conf.d/50unattended-upgrades: Unattended-Upgrade::Origins-Pattern { "origin=Debian,codename=${distro_codename},label=Debian-Security"; }; -
Install
needrestartso services restart automatically after library upgrades:sudo apt install -y needrestart # /etc/needrestart/needrestart.conf -> $nrconf{restart} = 'a'; -
Subscribe to debian-security-announce and watch security-tracker.debian.org.
-
Mirror locally for controlled rollouts:
sudo apt install -y apt-mirror # /etc/apt/mirror.list: deb http://deb.debian.org/debian bookworm main contrib non-free deb http://security.debian.org/debian-security bookworm-security main contrib non-free sudo apt-mirror -
Monitor file integrity with
debsumsand AIDE:sudo apt install -y debsums aide sudo debsums -ca # report only changed conffile-less files sudo aideinit && sudo mv /var/lib/aide/aide.db.new /var/lib/aide/aide.db sudo aide --check -
Apply CIS Debian Linux Benchmark hardening and review
auditdrules in/etc/audit/rules.d/.
Related Errors & Cross-Refs
Issues that commonly surface alongside node-chart.js — vulnerability — patch and remediation guide: apt lock contention, broken dpkg state, systemd ordering cycles, AppArmor denials, and firewall rule drift. Useful triage:
sudo dpkg --configure -a
sudo apt --fix-broken install
systemd-analyze critical-chain
sudo journalctl -k | grep -i apparmor | tail
cat /proc/sys/kernel/tainted
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Browse all common problems & solutions on the Tutorials Hub.
References & Further Reading
Primary reference: Debian Security Tracker. Manual pages useful on Debian 12:
man apt
man apt-get
man apt-mark
man dpkg
man systemctl
man journalctl
man nft
man apparmor
man unattended-upgrades
Other resources: The Debian Administrator’s Handbook, Debian Security FAQ, Debian Security Tracker, and per-package notes in /usr/share/doc/node-chart.js/ for components implicated in node-chart.js — vulnerability — patch and remediation guide.