What’s Vulnerable › Vulnerabilities

CVE-2021-25933

• Severity: medium (CVSS 4.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.0% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-05-20 · updated 2026-06-17
• Weakness: CWE-79

Description

In OpenNMS Horizon, versions opennms-1-0-stable through opennms-27.1.0-1; OpenNMS Meridian, versions meridian-foundation-2015.1.0-1 through meridian-foundation-2019.1.18-1; meridian-foundation-2020.1.0-1 through meridian-foundation-2020.1.6-1 are vulnerable to Stored Cross-Site Scripting, since the function `validateFormInput()` performs improper validation checks on the input sent to the `groupName` and `groupComment` parameters. Due to this flaw, an authenticated attacker could inject arbitrary script and trick other admin users into downloading malicious files which can cause severe damage to the organization using opennms.

Affected products

• The OpenNMS Group Horizon: from 1.0 before 27.1.1 — fixed in 27.1.1
• The OpenNMS Group Meridian: from 2015.1.0 before 2019.1.19; from 2020.1.0 before 2020.1.7 — fixed in 2019.1.19, 2020.1.7

How to fix

Upgrade to a fixed version: The OpenNMS Group Horizon 27.1.1; The OpenNMS Group Meridian 2019.1.19, 2020.1.7. Check the vendor advisory for mitigations.

References

• https://github.com/OpenNMS/opennms/commit/8a97e6869d6e49da18b208c837438ace80049c01%2C
• https://github.com/OpenNMS/opennms/commit/eb08b5ed4c5548f3e941a1f0d0363ae4439fa98c
• https://github.com/OpenNMS/opennms/commit/f3ebfa3da5352b4d57f238b54c6db315ad99f10e
• https://www.whitesourcesoftware.com/vulnerability-database/CVE-2021-25933
• https://github.com/OpenNMS/opennms/commit/8a97e6869d6e49da18b208c837438ace80049c01%2C
• https://github.com/OpenNMS/opennms/commit/eb08b5ed4c5548f3e941a1f0d0363ae4439fa98c
• https://github.com/OpenNMS/opennms/commit/f3ebfa3da5352b4d57f238b54c6db315ad99f10e
• https://www.whitesourcesoftware.com/vulnerability-database/CVE-2021-25933

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