CVE-2021-25931Public exploitNetwork attack vector

Administrator privilege escalation via unprotected user update

Published May 20, 2021 · Updated Apr 30, 2025

CSRF in OpenNMS Horizon and Meridian allows remote attackers to grant a normal user administrator privileges through the web console. The user-update endpoint applies submitted roles without validating a CSRF token; the upstream patch enables CSRF checks and adds tokens to administrative forms. Exploitation requires an authenticated administrator to visit an attacker-controlled site, after which a normal account receives the ROLE_ADMIN role.

CVSS severity8.8
High
EPSS probability0.73%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

CSRF in OpenNMS Horizon and Meridian allows remote attackers to grant a normal user administrator privileges through the web console. The user-update endpoint applies submitted roles without validating a CSRF token; the upstream patch enables CSRF checks and adds tokens to administrative forms. Exploitation requires an authenticated administrator to visit an attacker-controlled site, after which a normal account receives the ROLE_ADMIN role.

The record

CVE
CVE-2021-25931
Published
May 20, 2021
Updated
Apr 30, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-352, T1098
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 20, 2021CVE publishedPublication date reported by the CVE source.
  2. Apr 30, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.8MendCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
6.8NVDAV:N/AC:M/Au:N/C:P/I:P/A:P
8.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-352Cross-Site Request Forgery (CSRF)
T1098Account Manipulation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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