📖 ~4 min read • Source: FreeBSD VuXML
VuXML topic: py-pdfminer.six — Arbitrary Code Execution in pdfminer.six via Crafted PDF Input
Related CVEs: CVE-2025-64512
Upstream summary: Pieter Marsman reports: pdfminer.six will execute arbitrary code from a malicious pickle file if provided with a malicious PDF file. The CMapDB._load_data() function in pdfminer.six uses pickle.loads() to deserialize pickle files. These pickle files are supposed to be part of the pdfminer.six distribution stored in the cmap/ directory, but a malicious PDF can specify an alternative directory and filename as long as the filename ends in .pickle.gz. A malicious, zipped pickle f
Table of contents
Symptom & Impact
Nothing executes py313-pdfminer.six on its own; its code runs inside whatever links against or imports it, so the exposed surface on a FreeBSD 15 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. py313-pdfminer.six is a library — code loaded by other programs rather than a daemon — so there is no service to restart and service py313-pdfminer.six will simply report no such service; restart its consumers instead.
Environment & Reproduction
Reproduction targets FreeBSD 15. Confirm with freebsd-version -kru, uname -a, and the installed package via pkg info py313-pdfminer.six and pkg query "%n-%v" py313-pdfminer.six. Capture system state with pkg audit -F and service -e. Trigger the workflow that exposes py313-pdfminer.six while collecting tail -200 /var/log/messages, dmesg -a, and /var/log/pkg.log.
Root Cause Analysis
Root cause is tracked at FreeBSD VuXML. The FreeBSD ports security team shipped a corrective py313-pdfminer.six port revision; hosts on an outdated build remain exposed. Correlate /var/log/pkg.log with /var/log/messages and kernel state in sysctl kern.lastpid + sysctl kern.osreldate to isolate the change that triggered the failure mode.
Quick Triage
Quick triage: tail -100 /var/log/messages, pkg audit -F, pkg version -v py313-pdfminer.six, and pfctl -sr (or ipfw list) to confirm firewall posture. For kernel issues: dmesg -a | tail -100 and kldstat.
Step-by-Step Diagnosis
1) service -e to enumerate failed services. 2) tail -F /var/log/messages and dmesg. 3) Validate firewall via pfctl -sr -v or ipfw show. 4) pkg check -B py313-pdfminer.six for integrity. 5) pkg install -fy py313-pdfminer.six to reinstall if tampered. 6) Correlate findings with /var/log/pkg.log and FreeBSD VuXML to pin the commit that introduced the regression.
Solution – Primary Fix
Primary fix: install the corrective py313-pdfminer.six port revision referenced by FreeBSD VuXML. Typical commands: sudo pkg update, sudo pkg upgrade py313-pdfminer.six (or sudo pkg upgrade -y for the whole system), then and pkg audit to confirm no remaining advisories. For ports tree builders: sudo portsnap fetch update + cd /usr/ports/<cat>/py313-pdfminer.six && sudo make deinstall reinstall clean. Reboot if the kernel module is involved.
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Solution – Alternative Approaches
Alternatives include locking the package with sudo pkg lock py313-pdfminer.six until vetted, downgrading via pkg install <older-version> from a pinned repo, switching the FreeBSD pkg repository between quarterly and latest in /usr/local/etc/pkg/repos/FreeBSD.conf, isolating the affected service in a jail (iocage/bastille) with stricter firewall rules, or replacing the service with a vendored static build for the period between exposure detection and full rollout.
Verification & Acceptance Criteria
Acceptance: pkg info py313-pdfminer.six shows the expected fixed version is running, pkg audit returns no advisory for py313-pdfminer.six, tail -50 /var/log/messages shows no errors after restart, and the original reproduction for py313-pdfminer.six no longer triggers across two consecutive runs.
Rollback Plan
Capture state with pkg query "%n-%v" > /root/pkg-pre.txt and a ZFS boot-environment snapshot: bectl create pre-py313-pdfminer.six-patch. To revert, run sudo pkg install -f <previous-version> or boot the previous BE via bectl activate pre-py313-pdfminer.six-patch && reboot. For kernel/loader changes, drop to the loader prompt and select the previous boot environment.
Prevention & Hardening
Prevent recurrence by scheduling pkg audit -F via periodic.conf (daily_status_security_pkgaudit_enable="YES"), subscribing to freebsd-security-notifications, mirroring through a local pkg repo managed by poudriere, version-pinning sensitive packages with pkg lock, enabling automatic ZFS BE snapshots before upgrades, and monitoring file integrity via mtree or aide. Apply the CIS FreeBSD hardening checklist where applicable and harden jails with allow.* tunables in /etc/jail.conf.
Related Errors & Cross-Refs
Related issues that commonly surface alongside py313-pdfminer.six: pkg lock contention, mismatched ABI after kernel/userland skew (freebsd-version vs uname -K), pf rule drift, and stale shared-library references after upgrade (pkg check -d).
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References & Further Reading
Primary reference: FreeBSD VuXML. Supporting docs: FreeBSD Handbook, man pkg, man freebsd-update, man pfctl, man ipfw, man bectl, man periodic.conf, the FreeBSD Security Advisories at security.freebsd.org, and /usr/ports/UPDATING for port-specific notes implicated in this advisory.
