CVE-2021-25933

Exp

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.

Published: 2021-05-20 Last update: 2025-04-30 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-25933 is rated Exploit Available (56.3/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.45%). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2021-25933

EDB-ID Source Kind Published Link
nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-25933

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-10-11 0.34% 0.45% +0.12%
2 2025-03-31 0.46% 0.34% -0.12%
3 2025-03-17 0.46%

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-25933

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.8 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
1.7 2.7 [email protected]
4.8 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
1.7 2.7 134c704f-9b21-4f2e-91b3-4a467353bcc0
3.5 2.0 LOW
AV:N/AC:M/Au:S/C:N/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
6.8 2.9 [email protected]

Weakness enumeration for CVE-2021-25933

GitHub Security Advisory for CVE-2021-25933

GHSA-jjhw-5mxp-2g2q · Severity: medium · Ecosystem: maven — Cross-site Scripting in OpenNMS Horizon

Affected software / configurations for CVE-2021-25933

Vendor Product Version Raw CPE
opennms horizon >= 1.0, < 27.1.1 cpe:2.3:a:opennms:horizon:*:*:*:*:*:*:*:*
opennms meridian >= 2015.1.0, < 2019.1.19 cpe:2.3:a:opennms:meridian:*:*:*:*:*:*:*:*
opennms meridian >= 2020.1.0, < 2020.1.7 cpe:2.3:a:opennms:meridian:*:*:*:*:*:*:*:*

References for CVE-2021-25933

cvelogic Threat Intelligence