Path Traversal in linuxfabrik-lib (CVE-2026-73974)
Summary
Path traversal in linuxfabrik-lib (CVE-2026-73974). Confidential information can be exposed externally. Exploitable via nagios. Mitigation: upgrade to 6.1.0 or later.
Original description
The description as published by the source.
Summary
Every Linuxfabrik check plugin that supports the shared --test argument (routed through lib.lftest.test()) will, when --test is supplied, treat the first CSV element as a filesystem path and read its full contents as the plugin's simulated STDOUT — running as root when the plugin is invoked through the shipped nagios/icinga sudoers allowlist. --test is a live production argument (centrally mapped to argparse.SUPPRESS, so it is hidden from --help but still accepted on the command line), not a build-time-only gate. This yields an arbitrary root file-read primitive (full disclosure on deb-updates; filtered disclosure / existence-and-readability oracle on ~22 other whitelisted plugins), i.e. local privilege escalation from the nagios account to root.
Root Cause
lib.lftest.test(args)(lftest.pylines 659-664):stdout = args[0];if stdout and os.path.isfile(stdout): _, stdout = disk.read_file(stdout). Element[1] (stderr channel) is read the same way. There is no path confinement on the supplied path.check-plugins/deb-updates/deb-updates:--testis registered withtype=lib.args.csv(lines 78-82). When supplied, control flows tostdout, _, retc = lib.lftest.test(args.TEST)(line 143), bypassing the apt path (if args.TEST is None:at 121). Each returned line is stored as apackagerow and, under the default--query='1'(WHERE 1, matches all rows), every row is printed via'\n* '.join([row['package'] ...])→ `lib…
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-73974 has been found in linuxfabrik-lib.
Attackers can target a specific entry point like nagios over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 5.5/10.
What to do: upgrade linuxfabrik-lib to 6.1.0 or later.
If unsure, ask your IT team or search "linuxfabrik-lib CVE-2026-73974" on the vendor's site.
CVE-2026-73974 (linuxfabrik-lib) — CWE-22 / CVSS v3 5.5
Attack vector: local / no user interaction
Attack surface: nagios / icinga / argparse.SUPPRESS / lftest.py
Patched: 6.1.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Path traversal (CWE-22) exists in linuxfabrik-lib. Attackers reach the vulnerable code path via nagios.
Check the vendor advisory for the affected versions of linuxfabrik-lib. Attack surface: nagios / icinga / argparse.SUPPRESS / lftest.py.
Severity: Medium (CVSS 5.5/10). Confidential information can be exposed externally.
Update to 6.1.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'linuxfabrik-lib' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'linuxfabrik-lib' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
linuxfabrik-libを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade linuxfabrik-lib to 6.1.0ステージング環境で 6.1.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
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3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。