FreeBSD 14 — kf5-kconfig — vulnerability — patch and remediation guide

📖 ~4 min read  •  Source: FreeBSD VuXML

VuXML topic: KDE Frameworks — malicious .desktop files execute code

Related CVEs: CVE-2019-14744

Upstream summary: The KDE Community has released a security announcement: The syntax Key[$e]=$(shell command) in *.desktop files, .directory files, and configuration files (typically found in ~/.config) was an intentional feature of KConfig, to allow flexible configuration. This could however be abused by malicious people to make the users install such files and get code executed even without intentional action by the user.

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 FreeBSD 14 hosts that have kf5-kconfig installed, operators see behaviour consistent with the FreeBSD VuXML entry: pkg audit flags the installed version; any daemon, CLI tool, or application linked against kf5-kconfig may misbehave or fail to start after upgrade; and — for security-rated advisories — the host is exposed to the vulnerabilities above. Impact ranges from a single restart cycle to full availability incidents on jails, bhyve guests, or downstream consumers that depend on kf5-kconfig.

Environment & Reproduction

Reproduction targets FreeBSD 14. Confirm release, installed package, and capture baseline state:

freebsd-version -kru
uname -a
pkg info kf5-kconfig
pkg query "%n-%v" kf5-kconfig
pkg audit -F
service -e

Trigger the workflow that exposes kf5-kconfig — vulnerability — patch and remediation guide while collecting:

tail -200 /var/log/messages
dmesg -a | tail -200
tail -200 /var/log/pkg.log

Root Cause Analysis

Root cause is tracked at FreeBSD VuXML. The FreeBSD ports security team shipped a corrective kf5-kconfig port revision; hosts on an outdated build remain exposed. Correlate package logs with system logs and kernel state to isolate the change that triggered the failure mode:

tail -500 /var/log/pkg.log
tail -500 /var/log/messages
sysctl kern.lastpid
sysctl kern.osreldate     # numeric __FreeBSD_version, e.g. 1400097

Quick Triage

Run these checks on FreeBSD 14 to confirm the failure mode and current state of kf5-kconfig:

pkg version -v kf5-kconfig                # installed vs available version
pkg audit kf5-kconfig                     # advisory match for this package
tail -100 /var/log/messages
dmesg -a | tail -100
kldstat                              # kernel module state (for kernel/driver pkgs)
pfctl -sr 2>/dev/null || ipfw list   # only if pf/ipfw is enabled
# If kf5-kconfig ships an rc.d service (script name may differ from the pkg name,
# e.g. bind918→named, php83→php-fpm), check it:
service -e | grep -i kf5-kconfig && service <rc-script-name> status

Step-by-Step Diagnosis

1. List enabled services (only relevant if the package provides one).

   service -e

2. Follow live logs.

   tail -F /var/log/messages
   dmesg

3. Validate firewall rules (skip if neither pf nor ipfw is enabled).

   pfctl -sr -v 2>/dev/null || ipfw show

4. Check package integrity for kf5-kconfig.

   pkg check -B kf5-kconfig
   pkg check -d kf5-kconfig    # verify shared-library deps

5. Reinstall kf5-kconfig if integrity check fails.

   pkg install -fy kf5-kconfig

6. Correlate findings with /var/log/pkg.log and FreeBSD VuXML to pin the commit that introduced kf5-kconfig — vulnerability — patch and remediation guide.

Solution – Primary Fix

Install the corrective kf5-kconfig port revision referenced by FreeBSD VuXML:

sudo pkg update
sudo pkg upgrade kf5-kconfig              # or: sudo pkg upgrade -y for the whole system
# If kf5-kconfig provides an rc.d service, restart it (script name may differ from pkg name):
# sudo service <rc-script-name> restart
pkg audit kf5-kconfig                    # confirm no remaining advisory for this package

For ports-tree builders (FreeBSD 13.x and earlier used portsnap; on FreeBSD 14+ the ports tree is fetched with Git):

# FreeBSD 14+ (portsnap was removed):
sudo pkg install -y git-lite
sudo git clone --depth 1 https://git.FreeBSD.org/ports.git /usr/ports
# FreeBSD 13.x and earlier:
# sudo portsnap fetch update
cd /usr/ports/<category>/kf5-kconfig
sudo make deinstall reinstall clean

Reboot only if the package ships a kernel module or replaces a shared library used by long-running daemons.

Solution – Alternative Approaches

If the primary fix is not viable, choose from these alternatives:

• Lock the package until the fix is vetted:

  sudo pkg lock kf5-kconfig

• Downgrade to a known-good revision. pkg install pkgname-VERSION is not a real downgrade syntax — fetch a specific build instead:

  # 1. Discover available versions across configured repos:
  pkg search -e kf5-kconfig
  pkg rquery -r FreeBSD-quarterly '%n-%v' kf5-kconfig
  # 2. Install from a specific saved .pkg file:
  sudo pkg add -f /path/to/kf5-kconfig-<older-version>.pkg
  # 3. Or switch the host repo to the quarterly branch (see snippet below) and:
  sudo pkg upgrade -fr FreeBSD-quarterly kf5-kconfig

• Switch the pkg repository between quarterly and latest by editing /usr/local/etc/pkg/repos/FreeBSD.conf:

  FreeBSD: {
    url: "pkg+https://pkg.FreeBSD.org/${ABI}/quarterly",
    mirror_type: "srv",
    signature_type: "fingerprints",
    fingerprints: "/usr/share/keys/pkg",
    enabled: yes
  }

• Isolate the affected service in a jail with stricter firewall rules:

  iocage create -n kf5-kconfig-jail -r 14.1-RELEASE
  iocage set allow_raw_sockets=0 kf5-kconfig-jail
  # or with Bastille:
  bastille create kf5-kconfig-jail 14.1-RELEASE 10.0.0.10

• Replace the service with a vendored static build for the period between exposure detection and full rollout.

Verification & Acceptance Criteria

All of these should pass after the fix:

pkg info kf5-kconfig                # shows the expected fixed version
pkg audit kf5-kconfig               # no advisory for this package (exit code 0)
tail -50 /var/log/messages   # no new errors after upgrade
# If kf5-kconfig ships a service, confirm it is running under its rc.d name:
# service <rc-script-name> status

The original reproduction for kf5-kconfig — vulnerability — patch and remediation guide must not trigger across two consecutive runs.

Rollback Plan

Capture state before any change (only ZFS root has boot environments — UFS hosts skip bectl):

pkg query "%n-%v" > /root/pkg-pre.txt
# ZFS-on-root only:
sudo bectl create pre-kf5-kconfig-patch

To revert if the upgrade is bad, reinstall the previously saved .pkg file:

sudo pkg add -f /var/cache/pkg/kf5-kconfig-<previous-version>.pkg
# Or activate the pre-patch boot environment and reboot (ZFS-on-root only):
sudo bectl activate pre-kf5-kconfig-patch
sudo shutdown -r now

For kernel/loader changes on a UFS host, boot the previous kernel from the loader prompt (press 3 at the menu, then boot kernel.old).

Prevention & Hardening

Prevent recurrence on FreeBSD 14 hosts running kf5-kconfig:

• Enable the daily security pkg audit in /etc/periodic.conf:

  daily_status_security_pkgaudit_enable="YES"

• Subscribe to freebsd-security-notifications at lists.freebsd.org.

• Mirror through a local pkg repository managed by poudriere:

  poudriere jail -c -j 14amd64 -v 14.1-RELEASE
  poudriere ports -c -p default
  poudriere bulk -j 14amd64 -p default <category>/kf5-kconfig

• Version-pin sensitive packages:

  sudo pkg lock kf5-kconfig

• Take an automatic ZFS boot-environment snapshot before every upgrade (ZFS root only):

  sudo bectl create pre-upgrade-$(date +%Y%m%d)

• Monitor file integrity (create a baseline, verify against it later):

  # Create a baseline (use -c; target /usr/local/etc, /etc, /boot — NOT /):
  sudo mtree -c -K sha256digest -p /usr/local/etc > /var/db/usr-local-etc.mtree
  sudo mtree -c -K sha256digest -p /etc          > /var/db/etc.mtree
  # Verify later:
  sudo mtree -p /usr/local/etc < /var/db/usr-local-etc.mtree
  # Or with AIDE for a richer ruleset:
  sudo pkg install -y aide && sudo aide --init && sudo aide --check

• Harden jails with allow.* tunables in /etc/jail.conf:

  kf5-kconfig_jail {
    allow.raw_sockets = 0;
    allow.sysvipc    = 0;
    allow.mount      = 0;
    allow.chflags    = 0;
  }

Related Errors & Cross-Refs

Issues that commonly surface alongside kf5-kconfig — vulnerability — patch and remediation guide: pkg lock contention, mismatched ABI after kernel/userland skew, pf rule drift, and stale shared-library references after upgrade. Triage with:

freebsd-version -kru
uname -K
pkg check -d
pfctl -sr

View all freebsd-14 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Primary reference: FreeBSD VuXML. Useful manual pages on FreeBSD 14:

man pkg
man freebsd-update
man pfctl
man ipfw
man bectl
man periodic.conf

Other resources: the FreeBSD Handbook, the FreeBSD Security Advisories at security.freebsd.org, and the /usr/ports/UPDATING file for port-specific notes implicated in kf5-kconfig — vulnerability — patch and remediation guide.