Affected versions: SLES 12

πŸ“– ~4 min read  β€’  Source: SUSE advisory SUSE-CU-2020:177-1 (see also SUSE bugzilla)

Related CVEs: CVE-2019-18218 CVE-2012-1571 CVE-2014-3710 CVE-2014-8116 CVE-2014-8117 CVE-2019-8905 CVE-2019-8906 CVE-2019-8907  +4 more

Upstream summary: cdf_read_property_info in cdf.c in file through 5.37 does not restrict the number of CDF_VECTOR elements, which allows a heap-based buffer overflow (4-byte out-of-bounds write).

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 SLES 12 hosts running file, administrators report behaviour consistent with SUSE advisory SUSE-CU-2020:177-1: zypper refusing to install or restart affected services, AppArmor profile warnings in journalctl, and β€” for security-rated advisories β€” exposure to the vulnerability set above. In production estates the visible impact ranges from a single service restart to wider availability incidents whenever file sits on the serving path.

Environment & Reproduction

Reproduction targets SLES 12. Confirm release with cat /etc/os-release and SUSEConnect --status-text, and the currently installed package with rpm -q file. Capture system state with supportconfig -R /var/tmp -B file if you need to attach evidence to a SUSE support case. Trigger the workflow that exposes file β€” multiple vulnerabilities (12 CVEs) β€” patch and remediation guide while collecting journalctl -b, zypper history, and rpm -qa output.

Root Cause Analysis

Root cause is documented in SUSE advisory SUSE-CU-2020:177-1. Upstream maintainers shipped fixes in the corresponding file update for SLES 12; running an outdated build leaves the host exposed to the failure modes described in the advisory. Correlate journalctl --since timestamps with zypper history entries and any AppArmor denials in /var/log/audit/audit.log to isolate the originating change.

Quick Triage

Quick triage: run systemctl status file, journalctl -u file -n 200, zypper patch-check, zypper lp, firewall-cmd --list-all, and aa-status. If AppArmor is in enforce mode, capture journalctl -k | grep apparmor to surface denials linked to file β€” multiple vulnerabilities (12 CVEs) β€” patch and remediation guide.

Step-by-Step Diagnosis

1) Confirm symptom with systemctl --failed. 2) Inspect logs: journalctl -xe and journalctl -u file. 3) Validate firewall: firewall-cmd --list-all-zones. 4) Check AppArmor: aa-status and journalctl -k | grep apparmor. 5) Verify package integrity: rpm -V file and zypper verify. 6) Correlate findings with zypper history, /var/log/zypp/history, and SUSE advisory SUSE-CU-2020:177-1 to pin the change that introduced file β€” multiple vulnerabilities (12 CVEs) β€” patch and remediation guide.

Solution – Primary Fix

Primary fix for file β€” multiple vulnerabilities (12 CVEs) β€” patch and remediation guide: apply the corrective zypper transaction described in SUSE advisory SUSE-CU-2020:177-1, reload the affected systemd unit, and reconcile firewalld and AppArmor state. Typical commands: sudo zypper ref, sudo zypper -n patch or sudo zypper -n update file, sudo systemctl daemon-reload, sudo systemctl restart file, then rpm -q file to validate the new build is installed. For kernel advisories add sudo systemctl reboot or schedule a Live Patch (kgraft/klp) where covered by your SUSE subscription.

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Solution – Alternative Approaches

Alternatives include rolling back the offending transaction with sudo zypper history --rollback <id> (Btrfs Snapper snapshots make this safe on SLES 12), locking the package via sudo zypper al file, switching firewalld backends between nftables and iptables in /etc/firewalld/firewalld.conf, or temporarily disabling the AppArmor profile with sudo aa-disable /etc/apparmor.d/usr.sbin.file to confirm policy is the cause before authoring a custom profile. Where Live Patching is licensed, klp patches applies kernel fixes without reboot.

Verification & Acceptance Criteria

Acceptance: rpm -q file shows the expected fixed version, systemctl is-active file returns active, journalctl -u file --since "5 minutes ago" shows no errors, zypper patch-check reports zero open patches for this advisory, firewall-cmd --list-services includes the required services, aa-status reports the intended profile mode, and the original reproduction steps for file β€” multiple vulnerabilities (12 CVEs) β€” patch and remediation guide no longer trigger the failure across two consecutive runs.

Rollback Plan

Capture state with zypper history list, snapper list, and rpm -qa > /root/rpm-pre.txt before any change. To revert, run sudo snapper undochange <pre>..<post> on Btrfs deployments or sudo zypper install --oldpackage file-<old-version> and reload systemctl daemon-reload. Remove custom AppArmor profiles with sudo apparmor_parser -R. Reboot if the kernel or initramfs was changed and re-verify symptoms.

Prevention & Hardening

Prevent recurrence by enabling automatic security patches with zypper-automatic or YaST > Online Update Configuration, subscribing to the SUSE-SU mailing list, mirroring through SUSE Manager / RMT for controlled rollouts, version-locking sensitive packages with zypper al, and monitoring file integrity with aide --check. Apply CIS SLES 12 hardening, enable Snapper rollbacks on Btrfs root, and where supported enable SUSE Live Patching so future advisories like this can be remediated without reboot.

Related issues that commonly surface alongside file β€” multiple vulnerabilities (12 CVEs) β€” patch and remediation guide: zypper transaction lock contention, systemd unit ordering cycles, AppArmor denials in journalctl -k, firewalld zone drift, and kernel taint flags shown by cat /proc/sys/kernel/tainted. See sibling common-problem articles in this SLES 12 series for adjacent failure modes.

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References & Further Reading

Primary reference: SUSE advisory SUSE-CU-2020:177-1 (see also SUSE bugzilla). Supporting docs: SUSE Linux Enterprise Server Administration Guide, man zypper, man systemctl, man firewall-cmd, man aa-status, man snapper, man journalctl, the SUSE patch finder at suse.com/patches/, and the SUSE Live Patching documentation. Review /usr/share/doc/packages/file/ for component-level notes implicated in file β€” multiple vulnerabilities (12 CVEs) β€” patch and remediation guide.