How severe is CVE-2018-20434?

CVE-2018-20434 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2018-20434 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 71% (99th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-20434?

CVE-2018-20434 affects Librenms. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2018-20434?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2018-20434 published?

CVE-2018-20434 was published on 2019-04-24 and last updated on 2026-06-17.

CVE-2018-20434

CVE-2018-20434 is a critical-severity vulnerability in Librenms with a CVSS 3.x base score of 9.8. Its EPSS exploit-prediction score of 71% places it in the 99th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-78.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 10.0
EPSS exploit prediction: 71% (99th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-78
Affected product: Librenms
Published: 2019-04-24
Last modified: 2026-06-17

Description

LibreNMS 1.46 allows remote attackers to execute arbitrary OS commands by using the $_POST['community'] parameter to html/pages/addhost.inc.php during creation of a new device, and then making a /ajax_output.php?id=capture&format=text&type=snmpwalk&hostname=localhost request that triggers html/includes/output/capture.inc.php command mishandling.

Frequently asked questions

What is CVE-2018-20434?: LibreNMS 1.46 allows remote attackers to execute arbitrary OS commands by using the $_POST['community'] parameter to html/pages/addhost.inc.php during creation of a new device, and then making a /ajax_output.php?id=capture&format=text&type=snmpwalk&hostname=localhost request that triggers html/includes/output/capture.inc.php command mishandling.
How severe is CVE-2018-20434?: CVE-2018-20434 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2018-20434 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 71% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-20434?: CVE-2018-20434 affects Librenms. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-20434?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2018-20434 published?: CVE-2018-20434 was published on 2019-04-24 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:librenms:librenms:1.46:*:*:*:*:*:*:*

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