OpenNMS has a default password of rtc for the rtc account, which makes it easier for remote attackers to obtain access by leveraging knowledge of the credentials.

OpenNMS is accessible via port 9443

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 CSRF, due to no CSRF protection at /opennms/admin/userGroupView/users/updateUser. This flaw allows assigning ROLEADMIN security role to a normal user. Using this flaw, an attacker can trick the admin user to assign administrator privileges to a normal user by enticing him to click upon an attacker-controlled website.

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.

XXE injection in /rtc/post/ endpoint in OpenMNS Horizon 31.0.8 and versions earlier than 32.0.2 on multiple platforms is vulnerable to XML external entity (XXE) injection, which can be used for instance to force Horizon to make arbitrary HTTP requests to internal and external services. The solution is to upgrade to Meridian 2023.1.6, 2022.1.19, 2021.1.30, 2020.1.38 or Horizon 32.0.2 or newer. Meridian and Horizon installation instructions state that they are intended for installation within an organization's private networks and should not be directly accessible from the Internet. OpenNMS thanks Erik Wynter and Moshe Apelbaum for reporting this issue.

A BeanShell interpreter in remote server mode runs in OpenMNS Horizon versions earlier than 32.0.2 and in related Meridian versions which could allow arbitrary remote Java code execution. The solution is to upgrade to Meridian 2023.1.6, 2022.1.19, 2021.1.30, 2020.1.38 or Horizon 32.0.2 or newer. Meridian and Horizon installation instructions state that they are intended for installation within an organization's private networks and should not be directly accessible from the Internet.

An issue was discovered in OpenNMS Horizon before 26.0.1, and Meridian before 2018.1.19 and 2019 before 2019.1.7. The ActiveMQ channel configuration allowed for arbitrary deserialization of Java objects (aka ActiveMQ Minion payload deserialization), leading to remote code execution for any authenticated channel user regardless of its assigned permissions.

A missing authorization vulnerability in OpenNMS Horizon allows configuration changes without authentication. The Spring Security policy for the /api/v2 REST API defines authorization rules for every HTTP method except PATCH, so the shipped @PATCH configuration endpoints for event configuration and SNMP data collection (which enable and disable event definitions and data-collection sources) are reachable with no authorization enforced. An unauthenticated attacker able to reach the web UI can disable event definitions and SNMP data collection, suppressing event and alarm generation and stopping metric collection - silently degrading monitoring and detection - with the change persisted and reloaded into the running system.

The solution is to upgrade to Horizon 36.0.4 or newer. Meridian and Horizon installation instructions state that they are intended for installation within an organization's private networks and should not be directly accessible from the Internet.

The Horizon REST API includes a users endpoint in OpenMNS Horizon 31.0.8 and versions earlier than 32.0.2 on multiple platforms is vulnerable to elevation of privilege. The solution is to upgrade to Meridian 2023.1.6, 2022.1.19, 2021.1.30, 2020.1.38 or Horizon 32.0.2 or newer. Meridian and Horizon installation instructions state that they are intended for installation within an organization's private networks and should not be directly accessible from the Internet.

OpenNMS thanks Erik Wynter for reporting this issue.

OpenNMS Horizon and Meridian allows HQL Injection in element/nodeList.htm (aka the NodeListController) via snmpParm or snmpParmValue to addCriteriaForSnmpParm. This affects Horizon before 25.2.1, Meridian 2019 before 2019.1.4, Meridian 2018 before 2018.1.16, and Meridian 2017 before 2017.1.21.

A form can be manipulated with cross-site request forgery in multiple versions of OpenNMS Meridian and Horizon. This can potentially allow an attacker to gain access to confidential information and compromise integrity. The solution is to upgrade to Meridian 2023.1.1 or Horizon 31.0.6 or newer. Meridian and Horizon installation instructions state that they are intended for installation within an organization's private networks and should not be directly accessible from the Internet.

In OpenMNS Horizon 31.0.8 and versions earlier than 32.0.2 and related Meridian versions, any user that has the ROLEFILESYSTEMEDITOR can easily escalate their privileges to ROLEADMIN or any other role. The solution is to upgrade to Meridian 2023.1.5 or Horizon 32.0.2 or newer. Meridian and Horizon installation instructions state that they are intended for installation within an organization's private networks and should not be directly accessible from the Internet. OpenNMS thanks Erik Wynter for reporting this issue.

In OpenMNS Horizon 31.0.8 and versions earlier than 32.0.2, the file editor which is accessible to any user with ROLEFILESYSTEMEDITOR privileges is vulnerable to XXE injection attacks. The solution is to upgrade to Meridian 2023.1.5 or Horizon 32.0.2 or newer. Meridian and Horizon installation instructions state that they are intended for installation within an organization's private networks and should not be directly accessible from the Internet. OpenNMS thanks Erik Wynter for reporting this issue.

OpenNMS version 18.0.1 and prior are vulnerable to a stored XSS issue due to insufficient filtering of SNMP agent supplied data. By creating a malicious SNMP 'sysName' or 'sysContact' response, an attacker can store an XSS payload which will trigger when a user of the web UI views the data. This issue was fixed in version 18.0.2, released on September 20, 2016.

OpenNMS version 18.0.1 and prior are vulnerable to a stored XSS issue due to insufficient filtering of SNMP trap supplied data. By creating a malicious SNMP trap, an attacker can store an XSS payload which will trigger when a user of the web UI views the events list page. This issue was fixed in version 18.0.2, released on September 20, 2016.

Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') vulnerability in OpenNMS Horizon and Meridian applications allows SQL Injection.

Users should upgrade to Meridian 2024.2.6 or newer, or Horizon 33.16 or newer. Meridian and Horizon installation instructions state that they are intended for installation within an organization's private networks and should not be directly accessible from the Internet.

Potential Insertion of Sensitive Information into Jetty Log Files in multiple versions of OpenNMS Meridian and Horizon could allow disclosure of usernames and passwords if the logging level is set to debug. Users should upgrade to Meridian 2023.1.0 or newer, or Horizon 31.0.4. Meridian and Horizon installation instructions state that they are intended for installation within an organization's private networks and should not be directly accessible from the Internet.

Unauthenticated, stored cross-site scripting in the display of alarm reduction keys in multiple versions of OpenNMS Horizon and Meridian could allow an attacker access to confidential session information. Users should upgrade to Meridian 2023.1.0 or newer, or Horizon 31.0.4. Meridian and Horizon installation instructions state that they are intended for installation within an organization's private networks and should not be directly accessible from the Internet.

Reflected cross-site scripting in graph results in multiple versions of OpenNMS Meridian and Horizon could allow an attacker access to steal session cookies. Users should upgrade to Meridian 2023.1.0 or newer, or Horizon 31.0.4. Meridian and Horizon installation instructions state that they are intended for installation within an organization's private networks and should not be directly accessible from the Internet.

Multiple stored and reflected cross-site scripting vulnerabilities in webapp jsp pages in multiple versions of OpenNMS Meridian and Horizon could allow an attacker access to confidential session information. Users should upgrade to Meridian 2023.1.0 or newer, or Horizon 31.0.4. Meridian and Horizon installation instructions state that they are intended for installation within an organization's private networks and should not be directly accessible from the Internet.

Multiple stored XSS were found on different JSP files with unsanitized parameters in OpenMNS Horizon 31.0.8 and versions earlier than 32.0.2 on multiple platforms that allow an attacker to store on database and then load on JSPs or Angular templates. The solution is to upgrade to Meridian 2023.1.6, 2022.1.19, 2021.1.30, 2020.1.38 or Horizon 32.0.2 or newer. Meridian and Horizon installation instructions state that they are intended for installation within an organization's private networks and should not be directly accessible from the Internet. OpenNMS thanks Jordi Miralles Comins for reporting this issue.

Multiple reflected XSS were found on different JSP files with unsanitized parameters in OpenMNS Horizon 31.0.8 and versions earlier than 32.0.2 on multiple platforms that an attacker can modify to craft a malicious XSS payload. The solution is to upgrade to Meridian 2023.1.6, 2022.1.19, 2021.1.30, 2020.1.38 or Horizon 32.0.2 or newer. Meridian and Horizon installation instructions state that they are intended for installation within an organization's private networks and should not be directly accessible from the Internet. OpenNMS thanks Jordi Miralles Comins for reporting this issue.

A SQL injection vulnerability exists in the JasperReports-based reporting feature of multiple versions of OpenNMS Meridian and Horizon. A low-privileged authenticated user (ROLEUSER) can run the shipped, default-enabled online reports "Maintenance contracts expired" (AssetManagementMaintExpired) and "Maintenance contracts strategy" (AssetManagementMaintStrategy) via the reporting REST API (POST /rest/reports/{id}) and supply a DATEFORMAT parameter that the report templates substitute literally, un-escaped, into their SQL queries. This lets an attacker execute arbitrary SQL against the OpenNMS database and read arbitrary data, including database-stored secrets such as provisioning and notification credentials and SNMP community strings.

The solution is to upgrade to Meridian 2024.3.13, 2025.0.10 and Horizon 36.0.4 or newer. Meridian and Horizon installation instructions state that they are intended for installation within an organization's private networks and should not be directly accessible from the Internet.

Cross-site scripting in outage/list.htm in multiple versions of OpenNMS Meridian and Horizon allows an attacker access to confidential session information. The solution is to upgrade to Meridian 2023.1.0 or newer, or Horizon 31.0.4 or newer.

Meridian and Horizon installation instructions state that they are intended for installation within an organization's private networks and should not be directly accessible from the Internet.

Cross-site scripting in bootstrap.jsp in multiple versions of OpenNMS Meridian and Horizon allows an attacker access to confidential session information. The solution is to upgrade to Horizon 32.0.5 or newer and Meridian 2023.1.9 or newer

Meridian and Horizon installation instructions state that they are intended for installation within an organization's private networks and should not be directly accessible from the Internet.

OpenNMS thanks

Moshe Apelbaum

for reporting this issue.

An XML External Entity (XXE) vulnerability exists in the XML collector of multiple versions of OpenNMS Meridian and Horizon. When OpenNMS collects XML from a source whose response is attacker-controlled (for example a compromised monitored host or an HTTP man-in-the-middle position), the collector's XML parser resolves external entities and external DTDs. This allows an attacker to read files accessible to the OpenNMS service account, including database credentials, and to induce out-of-band requests.

The solution is to upgrade to Meridian 2024.3.13, 2025.0.10 and Horizon 36.0.4 or newer. Meridian and Horizon installation instructions state that they are intended for installation within an organization's private networks and should not be directly accessible from the Internet.

A JEXL expression sandbox bypass exists in multiple versions of OpenNMS Meridian and Horizon. A low-privileged authenticated user can submit a crafted expression to the Measurements REST API that escapes the sandbox and loads arbitrary Java classes on the server. This can potentially allow an attacker to gain access to confidential information and compromise integrity.

The solution is to upgrade to Meridian 2024.3.12, 2025.0.9 and Horizon 36.0.3 or newer. Meridian and Horizon installation instructions state that they are intended for installation within an organization's private networks and should not be directly accessible from the Internet.

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 userID parameter. Due to this flaw an attacker could inject an arbitrary script which will be stored in the database.

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.

In OpenNMS Horizon, versions opennms-18.0.0-1 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 createRequisitionedNode() does not perform any validation checks on the input sent to the node-label parameter. Due to this flaw an attacker could inject an arbitrary script which will be stored in the database.