CVE-2025-3506Network attack vector

Unauthenticated custom agent file disclosure

Published May 8, 2025 · Updated May 8, 2025

Information disclosure in affected Checkmk releases allows remote attackers to read custom agent files over HTTP without authentication. The site Apache configuration exposes local/share/check_mk/agents at /sitename/check_mk/local/agents/ and serves files placed there by the custom-file deployment rule. Exposure requires custom files to be present in that directory; any secrets stored in those files become readable, while no integrity or availability impact is reported.

CVSS severity6.3
Medium
EPSS probability0.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in affected Checkmk releases allows remote attackers to read custom agent files over HTTP without authentication. The site Apache configuration exposes local/share/check_mk/agents at /sitename/check_mk/local/agents/ and serves files placed there by the custom-file deployment rule. Exposure requires custom files to be present in that directory; any secrets stored in those files become readable, while no integrity or availability impact is reported.

The record

CVE
CVE-2025-3506
Published
May 8, 2025
Updated
May 8, 2025
Vendor
Checkmk GmbH
Product
Checkmk
Classifications
CWE-497, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 8, 2025CVE publishedPublication date reported by the CVE source.
  2. May 8, 2025Record 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=2.1.0 <=2.1.0p50
  2. Affected versionversion=2.2.0
  3. Affected versionversion=2.3.0
  4. Affected versionversion=2.4.0 <2.4.0b6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Checkmk GmbH · Checkmkversion=2.1.0 <=2.1.0p50; version=2.2.0; version=2.3.0; version=2.4.0 <2.4.0b6

Published CVSS scores

5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
6.3Checkmk GmbHCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:N/SA: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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-497Exposure of Sensitive System Information to an Unauthorized Control Sphere
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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