How severe is CVE-2016-2056?

CVE-2016-2056 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2016-2056 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 55% (99th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-2056?

CVE-2016-2056 primarily affects Xymon. In total, 44 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2016-2056?

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

When was CVE-2016-2056 published?

CVE-2016-2056 was published on 2016-04-13 and last updated on 2026-06-17.

CVE-2016-2056

CVE-2016-2056 is a high-severity vulnerability in Xymon with a CVSS 3.x base score of 8.8. Its EPSS exploit-prediction score of 55% places it in the 99th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-77.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 6.5
EPSS exploit prediction: 55% (99th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-77
Affected product: Xymon
Published: 2016-04-13
Last modified: 2026-06-17

Description

xymond in Xymon 4.1.x, 4.2.x, and 4.3.x before 4.3.25 allow remote authenticated users to execute arbitrary commands via shell metacharacters in the adduser_name argument in (1) web/useradm.c or (2) web/chpasswd.c.

Frequently asked questions

What is CVE-2016-2056?: xymond in Xymon 4.1.x, 4.2.x, and 4.3.x before 4.3.25 allow remote authenticated users to execute arbitrary commands via shell metacharacters in the adduser_name argument in (1) web/useradm.c or (2) web/chpasswd.c.
How severe is CVE-2016-2056?: CVE-2016-2056 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2016-2056 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 55% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-2056?: CVE-2016-2056 primarily affects Xymon. In total, 44 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2016-2056?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2016-2056 published?: CVE-2016-2056 was published on 2016-04-13 and last updated on 2026-06-17.

References

Affected products (44)

cpe:2.3:a:xymon:xymon:4.1.0:*:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.1.1:*:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.1.2:*:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.1.2:p1:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.1.2:p2:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.2:alfa:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.2:beta20060605:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.2:rc20060712:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.2.0:*:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.2.2:*:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.2.2:rc1:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.2.3:*:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.2.3:rc1:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.3.0:*:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.3.0:beta1:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.3.0:beta2:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.3.0:beta3:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.3.0:rc1:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.3.1:*:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.3.2:*:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.3.3:*:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.3.4:*:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.3.5:*:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.3.6:*:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.3.7:*:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.3.8:*:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.3.9:*:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.3.10:*:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.3.11:*:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.3.12:*:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.3.13:*:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.3.14:*:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.3.15:*:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.3.16:*:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.3.17:*:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.3.18:*:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.3.19:*:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.3.19:rc1:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.3.20:*:*:*:*:*:*:*
cpe:2.3:a:xymon:xymon:4.3.21:*:*:*:*:*:*:*

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