How severe is CVE-2023-0871?

CVE-2023-0871 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability low.

Is CVE-2023-0871 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-0871?

CVE-2023-0871 primarily affects Opennms Horizon. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-0871?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2023-0871 published?

CVE-2023-0871 was published on 2023-08-11 and last updated on 2026-06-17.

CVE-2023-0871

CVE-2023-0871 is a medium-severity vulnerability in Opennms Horizon with a CVSS 3.x base score of 5.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-611.

Key facts

Severity: Medium (CVSS 3.x base score 5.4)
EPSS exploit prediction: 0% (39th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-611
Affected product: Opennms Horizon
Published: 2023-08-11
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2023-0871?: 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.
How severe is CVE-2023-0871?: CVE-2023-0871 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability low.
Is CVE-2023-0871 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-0871?: CVE-2023-0871 primarily affects Opennms Horizon. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-0871?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-0871 published?: CVE-2023-0871 was published on 2023-08-11 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:opennms:horizon:*:*:*:*:*:*:*:*
cpe:2.3:a:opennms:horizon:31.0.8:*:*:*:*:*:*:*
cpe:2.3:a:opennms:meridian:*:*:*:*:*:*:*:*

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