CVE-2021-25935

Exp

In OpenNMS Horizon, versions opennms-17.0.0-1 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-2020.1.7-1 are vulnerable to Stored Cross-Site Scripting, since the function `add()` performs improper validation checks on the input sent to the `foreign-source` parameter. Due to this flaw an attacker could bypass the existing regex validation and inject an arbitrary script which will be stored in the database.

Published: 2021-05-25 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-25935 is rated Exploit Available (53/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.26%). 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-2021-25935

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

Exploit prediction scoring system (EPSS) score for CVE-2021-25935

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 2025-03-30 0.23% 0.26% +0.03%
2 2025-03-29 0.26% 0.23% -0.03%
3 2025-03-17 0.26%

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-25935

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.4 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/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:L)
A normal user session is enough; they don’t have to be admin.
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.
2.3 2.7 [email protected]
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-2021-25935

Affected software / configurations for CVE-2021-25935

Vendor Product Version Raw CPE
opennms horizon >= 17.0.0, <= 27.1.0 cpe:2.3:a:opennms:horizon:*:*:*:*:*:*:*:*
opennms meridian >= 2015.1.0, <= 2019.1.18 cpe:2.3:a:opennms:meridian:*:*:*:*:*:*:*:*
opennms meridian >= 2020.1.0, <= 2020.1.7 cpe:2.3:a:opennms:meridian:*:*:*:*:*:*:*:*

References for CVE-2021-25935

cvelogic Threat Intelligence