GHSA-798h-hpph-m24j
HIGHGHSA-798h-hpph-m24j is a high-severity (CVSS 7.8) OS Command Injection vulnerability in linuxfabrik-lib. O3 Security confirms whether GHSA-798h-hpph-m24j is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Linuxfabrik Monitoring Plugins have local privilege escalation using embedded command
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for GHSA-798h-hpph-m24j.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-798h-hpph-m24j plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 372,613 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
linuxfabrik-libReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Summary
When a check plugin places user provided input inside a command which is passed to shell_exec, an attacker can abuse this to run arbitrary commands. This is mainly dangerous for plugins which are listed in the sudoers file, because this allows an attacker controlling the nagios user to get root privileges.
Details
An example for this is the restic-check plugin, where the --repo argument is placed inside the command argument of shell_exec. As an example, an attacker could use the --repo argument |touch /root/nagios-was-here|. The full restic command is assembled to the string restic --json --repo=|touch /root/nagios-was-here| --password-file= check before it is passed to shell_exec. shell_exec then splits the command up in three parts at the | boundaries and executes the parts separately, which also executes the embedded command touch /root/nagios-was-here.
PoC
This PoC shows how the nagios user can use this to create a file inside /root.
nagios@test-vm:/$ sudo /usr/lib64/nagios/plugins/restic-check --repo '|touch /root/nagios-was-here|'
Impact
The vulnerability is a local privilege escalation.
Fix
Switch from | to an array
Remove the | split functionality. Instead, modify shell_exec to accept either a string or an array of strings. If an array is provided, the commands are chained together like they currently are when using |. If a string is provided, no split should be performed. You could also introduce a separate function like shell_exec_with_user_input() which implements this such that the current shell_exec function can stay like it is.
This leaves the problem that an attacker can still specify arbitrary arguments inside a command. An example for this would be to use the --repo argument sftp://example.com --cache-dir /tmp, which would lead to the execution of: restic --json --repo=sftp://example.com --cache-dir /tmp --password-file=None check. Please note that this example should mainly highlight the problem in general. To prevent the problem, there is either escaping or again array-syntax. Escaping would use shlex.quote to place the user provided argument inside quotes and which also escapes everything which needs to be escaped. Using array syntax would mean providing the full command as an array like ['restic', '--json', '--repo', 'sftp://example.com']. The array can then be given as-is to Popen. With this method, the proposed shell_exec_with_user_input would accept an array of array of strings.
Patches
The fix follows the array-syntax approach proposed above:
linuxfabrik-lib5.0.0:lib.shell.shell_exec()requires the command as a list of arguments (argv) and always runs withshell=False. The|split functionality, command strings and theshell=parameter have been removed, so user-provided input can no longer break out of a command.lib.shell.safe_cli_value()additionally guards positional arguments (such as an ssh destination or a ping target) against option injection, andlib.sshbuilds argument lists as well.- Linuxfabrik Monitoring Plugins: all plugins assemble their external commands as argv lists (commit 23bb570f4). Contained in every release after v5.2.0.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | linuxfabrik-lib | all versions | 5.0.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for linuxfabrik-lib. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update linuxfabrik-lib to 5.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-798h-hpph-m24j is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-798h-hpph-m24j is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-798h-hpph-m24j. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-798h-hpph-m24j in your dependencies?
O3 detects GHSA-798h-hpph-m24j across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.