FreeBSD 13 — qt5-gui — multiple vulnerabilities (5 CVEs) — patch and remediation guide

📖 ~4 min read  •  Source: FreeBSD VuXML

VuXML topic: qt4-imageformats, qt4-gui, qt5-gui — Multiple Vulnerabilities in Qt Image Format Handling

Related CVEs: CVE-2014-0190 CVE-2015-0295 CVE-2015-1858 CVE-2015-1859 CVE-2015-1860

Upstream summary: Richard J. Moore reports: Due to two recent vulnerabilities identified in the built-in image format handling code, it was decided that this area required further testing to determine if further issues remained. Fuzzing using afl-fuzz located a number of issues in the handling of BMP, ICO and GIF files. The issues exposed included denial of service and buffer overflows leading to heap corruption. It is possible the latter could be used to perform remote code execution.

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

Nothing executes qt5-gui on its own; its code runs inside whatever links against or imports it, so the exposed surface on a FreeBSD 13 host is the union of every process that has loaded it — web workers, cron jobs, mail handlers, backup agents. The package manager replaces the files on disk, but processes already running keep the old build mapped, and virtualenvs, vendored copies and container images each carry their own copy, so a host can report itself patched while still running vulnerable code. qt5-gui is a library — code loaded by other programs rather than a daemon — so there is no service to restart and service qt5-gui will simply report no such service; restart its consumers instead.

Environment & Reproduction

Reproduction targets FreeBSD 13. Confirm release, installed package, and capture baseline state:

freebsd-version -kru
uname -a
pkg info qt5-gui
pkg query "%n-%v" qt5-gui
pkg audit -F
service -e

Exercise the workload that uses qt5-gui 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 The FreeBSD ports security team shipped a corrective qt5-gui port revision; hosts on an outdated build remain exposed.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 13 to confirm the failure mode and current state of qt5-gui:

pkg version -v qt5-gui                # installed vs available version
pkg audit qt5-gui                     # 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
# e.g. bind918→named, php83→php-fpm), check it:
pkg query '%Fp' qt5-gui | sed -n 's|.*/etc/rc\.d/||p'  # FreeBSD: the REAL service name(s) = basename of the rc.d script (bind918 -> named, postgresql16-server -> postgresql, apache24 -> apache24)
pkg query '%b' qt5-gui  # FreeBSD: shared libraries PROVIDED by qt5-gui. Non-empty here + no rc.d script = it is a library: patch it, then restart its consumers

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 qt5-gui.

   pkg check -B qt5-gui
   pkg check -d qt5-gui    # verify shared-library deps

5. Reinstall qt5-gui if integrity check fails.

   pkg install -fy qt5-gui

6. Correlate findings with /var/log/pkg.log and FreeBSD VuXML to pin the commit that introduced the regression.

Solution – Primary Fix

Install the corrective qt5-gui port revision referenced by FreeBSD VuXML:

sudo pkg update
sudo pkg upgrade qt5-gui              # or: sudo pkg upgrade -y for the whole system
pkg audit qt5-gui                    # 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>/qt5-gui
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 qt5-gui

• 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 qt5-gui
  pkg rquery -r FreeBSD-quarterly '%n-%v' qt5-gui
  # 2. Install from a specific saved .pkg file:
  sudo pkg add -f /path/to/qt5-gui-<older-version>.pkg
  # 3. Or switch the host repo to the quarterly branch (see snippet below) and:
  sudo pkg upgrade -fr FreeBSD-quarterly qt5-gui

• 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 qt5-gui-jail -r 13.4-RELEASE
  iocage set allow_raw_sockets=0 qt5-gui-jail
  # or with Bastille:
  bastille create qt5-gui-jail 13.4-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 qt5-gui                # shows the expected fixed version
pkg audit qt5-gui               # no advisory for this package (exit code 0)
tail -50 /var/log/messages   # no new errors after upgrade
# If qt5-gui ships a service, confirm it is running under its rc.d name:

The conditions described in the advisory must no longer be reported for qt5-gui 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-qt5-gui-patch

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

sudo pkg add -f /var/cache/pkg/qt5-gui-<previous-version>.pkg
# Or activate the pre-patch boot environment and reboot (ZFS-on-root only):
sudo bectl activate pre-qt5-gui-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 13 hosts running qt5-gui:

• 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 13amd64 -v 13.4-RELEASE
  poudriere ports -c -p default
  poudriere bulk -j 13amd64 -p default <category>/qt5-gui

• Version-pin sensitive packages:

  sudo pkg lock qt5-gui

• 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:

  qt5-gui_jail {
    allow.raw_sockets = 0;
    allow.sysvipc    = 0;
    allow.mount      = 0;
    allow.chflags    = 0;
  }

Related Errors & Cross-Refs

Issues that commonly surface alongside a qt5-gui update: 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-13 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 13:

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 this advisory.