CVE-2016-6556Public exploitNetwork attack vector

Stored XSS via unsanitized SNMP agent fields

Published Jun 15, 2022 · Updated Sep 16, 2024

Stored XSS in OpenNMS Horizon 18.0.1 and earlier allows remote attackers to run script in a web UI user's browser via SNMP agent data. During discovery, OpenNMS stores unfiltered sysName and sysContact values returned for their SNMP OIDs and renders them on the node page without safe output encoding. The malicious node must be discovered and scanned, and an authenticated user must view its page; the script then gains that browser session's access to cookies and privileged web operations.

CVSS severity6.1
Medium
EPSS probability0.84%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Stored XSS in OpenNMS Horizon 18.0.1 and earlier allows remote attackers to run script in a web UI user's browser via SNMP agent data. During discovery, OpenNMS stores unfiltered sysName and sysContact values returned for their SNMP OIDs and renders them on the node page without safe output encoding. The malicious node must be discovered and scanned, and an authenticated user must view its page; the script then gains that browser session's access to cookies and privileged web operations.

The record

CVE
CVE-2016-6556
Published
Jun 15, 2022
Updated
Sep 16, 2024
Vendor
The OpenNMS Group, Inc.
Product
OpenNMS Horizon
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 15, 2022CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=18.0.1 <=18.0.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The OpenNMS Group, Inc. · OpenNMS Horizonversion=18.0.1 <=18.0.1

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:P/A:N
7.1Rapid7, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N
6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007Command and Scripting Interpreter: JavaScript

Public exploit references

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

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo