📖 ~4 min read • Source: FreeBSD VuXML
VuXML topic: groovy — remote execution of untrusted code/DoS vulnerability
Related CVEs: CVE-2015-3253 CVE-2016-6814
Upstream summary: The Apache Groovy project reports: When an application with Groovy on classpath uses standard Java serialization mechanisms, e.g. to communicate between servers or to store local data, it is possible for an attacker to bake a special serialized object that will execute code directly when deserialized. All applications which rely on serialization and do not isolate the code which deserializes objects are subject to this vulnerability. This is similar to CVE-2015-3253 but this
Table of contents
Symptom & Impact
groovy is executed by every process started from it, so a flaw here surfaces inside your applications rather than in groovy itself: header-parsing and request-smuggling bugs in the bundled HTTP stack, weaknesses in the runtime’s own TLS and crypto code, unsafe archive, XML or deserialisation handling in the standard library, or memory-safety bugs in the JIT. Long-lived workers such as application servers, JVM daemons and resident node processes keep executing the old build after FreeBSD 15 replaces it on disk, so a patched machine stays exposed until each one is restarted. groovy is an interpreter or virtual machine plus its standard library, not a daemon: it runs only inside processes you start, so there is no groovy service to restart — restart the applications that execute it instead.
Environment & Reproduction
Reproduction targets FreeBSD 15. Confirm with freebsd-version -kru, uname -a, and the installed package via pkg info groovy and pkg query "%n-%v" groovy. Capture system state with pkg audit -F and service -e. Trigger the workflow that exposes groovy 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 The FreeBSD ports security team shipped a corrective groovy port revision; hosts on an outdated build remain exposed.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 groovy, 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 groovy for integrity. 5) pkg install -fy groovy 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 groovy port revision referenced by FreeBSD VuXML. Typical commands: sudo pkg update, sudo pkg upgrade groovy (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>/groovy && 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 groovy 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 groovy shows the expected fixed version is running, pkg audit returns no advisory for groovy, tail -50 /var/log/messages shows no errors after restart, and the original reproduction for groovy 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-groovy-patch. To revert, run sudo pkg install -f <previous-version> or boot the previous BE via bectl activate pre-groovy-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 groovy: 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.
