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HorizonApplication · Opennms

CVE-2021-3396

HIGH · 8.8 CVSS v3.1 Published 2021-02-17
Fix available
A fix is available. Upgrade to 1.5.3 / 2018.1.25 or later.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
OpenNMS Meridian 2016, 2017, 2018 before 2018.1.25, 2019 before 2019.1.16, and 2020 before 2020.1.5, Horizon 1.2 through 27.0.4, and Newts <1.5.3 has Incorrect Access Control, which allows local and remote code execution using JEXL expressions.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

OpenNMS contains an Incorrect Access Control vulnerability that allows authenticated users to execute arbitrary code through JEXL (Java Expression Language) expressions. The vulnerability affects Meridian, Horizon, and Newts products across multiple version ranges, enabling both local and remote code execution depending on attacker positioning.

MitigationUpgrade to Meridian 2018.1.25+, 2019.1.16+, or 2020.1.5+; Horizon 27.0.5+; or Newts 1.5.3+ to obtain the patch. Alternatively, restrict network access to administrative interfaces and validate that JEXL expression evaluation is properly scoped.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
HorizonApplication
Affected:>= 16.0.0, <= 27.0.3
MeridianApplication
Affected:>= 2016.1.0, <= 2016.1.24>= 2017.1.0, <= 2017.1.26>= 2018.1.0, < 2018.1.25>= 2019.1.0, < 2019.1.16>= 2020.1.0, < 2020.1.5
NewtsApplication
Affected:< 1.5.3

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify OpenNMS product and installed version
    Run 'opennms -v' or check the RPM/DEB package version with 'rpm -q opennms' or 'dpkg -l | grep opennms'. For Meridian, check the /opt/opennms/etc/version.properties file or the banner displayed on login.
    Affected if The product is Horizon, Meridian, or Newts and the version falls within the affected ranges (Horizon: 16.0.0-27.0.3; Meridian: 2016.1.0-2016.1.24, 2017.1.0-2017.1.26, 2018.1.0-2018.1.24, 2019.1.0-2019.1.15, 2020.1.0-2020.1.4; Newts: any version below 1.5.3)
  2. Confirm the /opennms/api/v2/measurements endpoint is accessible
    Check if the REST API endpoint /opennms/api/v2/measurements is reachable from the network or locally via curl to https://localhost:8980/opennms/api/v2/measurements
    Affected if The endpoint is accessible and responds to authenticated requests, enabling the JEXL expression injection vector
  3. Verify user authentication is enabled
    Review the etc/core.xml or etc/security.properties configuration files to confirm that authentication is not disabled (look for 'org.opennms.web.authentication.enabled=true' or similar settings)
    Affected if The system allows authenticated users to access the REST API, which is required to exploit the JEXL expression evaluation feature
  4. Check if JEXL expression evaluation is in use
    Review any existing data collection definitions in etc/datacollection/*.xml for '<expression>' or '<jexl>' tags, or examine scheduled reports that may use JEXL-based expressions
    Affected if JEXL expression evaluation is configured in data collection or reporting features, as this is the attack surface for code execution

A user is affected if they are running any Horizon version 16.0.0 through 27.0.3, any Meridian version 2016.1.0-2016.1.24, 2017.1.0-2017.1.26, 2018.1.0-2018.1.24, 2019.1.0-2019.1.15, or 2020.1.0-2020.1.4, or any Newts version below 1.5.3, with authenticated API access enabled.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to 1.5.3 / 2018.1.25 / 2019.1.16 or later
Fixed in 1.5.32018.1.252019.1.16
Interim mitigation

Upgrade to Meridian 2018.1.25+, 2019.1.16+, or 2020.1.5+; Horizon 27.0.5+; or Newts 1.5.3+ to obtain the patch. Alternatively, restrict network access to administrative interfaces and validate that JEXL expression evaluation is properly scoped.

Fix this in Horizon Scoped from the published advisory
  • Consultation8.0 h
  • Implementation16.0 h
  • Testing12.0 h
  • Review / QA4.0 h
40.0 hours of engineering $7,000
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-3396 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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