CVE-2023-0871

Arbitrary HTTP requests via conditional entity disabling

Published Aug 11, 2023 · Updated Oct 1, 2024

XXE injection in OpenNMS Horizon and Meridian allows attackers to force arbitrary HTTP requests through the RTC POST endpoint. The JaxbUtils XML filter disabled external general and parameter entities only when its disableDOCTYPE flag was set, leaving other parser calls able to resolve attacker-supplied entities. Reachability requires network access to an installation intended for a protected intranet; published assessments disagree on whether authentication is required.

CVSS severity5.4
Medium
EPSS probability0.55%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

XXE injection in OpenNMS Horizon and Meridian allows attackers to force arbitrary HTTP requests through the RTC POST endpoint. The JaxbUtils XML filter disabled external general and parameter entities only when its disableDOCTYPE flag was set, leaving other parser calls able to resolve attacker-supplied entities. Reachability requires network access to an installation intended for a protected intranet; published assessments disagree on whether authentication is required.

The record

CVE
CVE-2023-0871
Published
Aug 11, 2023
Updated
Oct 1, 2024
Vendor
The OpenNMS Group, Inc.
Product
OpenNMS Meridian
Classifications
CWE-611, T1190
Attack vector
adjacent
Privileges
Unavailable

Timeline

How it unfolded

  1. Aug 11, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 1, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=2020.0.0 <2020.1.38
  2. Affected versionversion=2021.0.0 <2021.1.30
  3. Affected versionversion=2022.0.0 <2022.1.19
  4. Affected versionversion=2023.0.0 <2023.1.6

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesUnavailable in this record.

What is affected?

The OpenNMS Group, Inc. · OpenNMS Meridianversion=2020.0.0 <2020.1.38; version=2021.0.0 <2021.1.30; version=2022.0.0 <2022.1.19; version=2023.0.0 <2023.1.6
The OpenNMS Group, Inc. · OpenNMS Horizonversion=31.0.8 <32.0.2

Published CVSS scores

6.1National Vulnerability DatabaseCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
8.8GitHub Advisory DatabaseCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:L
5.4The OpenNMS GroupCVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:L

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)
Vectoradjacent
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-611Improper Restriction of XML External Entity Reference
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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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