Security readout for executives and security teams
Plain-English summary
This vulnerability lets a logged-in OpenNMS user store malicious script through a notification wizard name field. If an administrator later interacts with it, the script could influence that admin session and trick them into downloading malicious files. The source bundle does not indicate public active exploitation.
Executive priority
Treat as a moderate-priority administrative console issue. It is not remotely exploitable without credentials, but it can affect administrators and should be fixed during normal vulnerability remediation cycles, faster for internet-exposed or shared-admin environments.
Technical view
CVE-2021-25929 is stored cross-site scripting in OpenNMS Horizon and Meridian. The noticeWizard endpoint did not validate the name parameter. CVSS 3.1 is 4.8, with network access, low complexity, high privileges required, user interaction required, changed scope, and low confidentiality and integrity impact.
Likely exposure
Exposure is limited to OpenNMS Horizon versions opennms-1-0-stable through 27.1.0-1 and specified Meridian 2015, 2019, and 2020 foundation ranges. Risk is higher where many privileged users administer OpenNMS or the admin interface is broadly reachable.
Exploitation context
The attacker must already be authenticated with high privileges, then rely on another admin user interacting with stored content. KEV is false in the supplied bundle, and no cited source states active exploitation. The main concern is admin-session abuse and malicious file download social engineering.
Researcher notes
Evidence supports stored XSS in the noticeWizard name parameter and affected version ranges. The bundle includes OpenNMS commits but does not name exact fixed release versions or operational mitigations. Avoid assuming exploitation beyond the stated authenticated, high-privilege, user-interaction scenario.
Mitigation direction
- Identify all OpenNMS Horizon and Meridian deployments and versions.
- Check OpenNMS vendor guidance for fixed releases or supported remediation.
- Upgrade affected instances according to vendor-supported guidance.
- Restrict OpenNMS administrative access to trusted networks and users.
- Review privileged OpenNMS accounts for unnecessary access.
Validation and detection
- Confirm installed versions are outside the affected ranges.
- Verify noticeWizard name input is validated or sanitized after remediation.
- Review administrative user activity around notification wizard changes.
- Check whether referenced OpenNMS commits are included in your deployed build.
- Confirm no unexpected files or scripts are linked from admin-facing notices.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-25929 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 4.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N1.72.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
4.8MediumVector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/OpenNMS/opennms/commit/eb08b5ed4c5548f3e941a1f0d0363ae4439fa98cCVE reference · x_refsource_MISC
- https://www.whitesourcesoftware.com/vulnerability-database/CVE-2021-25929CVE reference · x_refsource_MISC
- https://github.com/OpenNMS/opennms/commit/66c1f626bf38a7d1a9530b4d68598269ee5245a2CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.