Stored cross-site scripting in the service discovery active check output in Checkmk <2.5.0p5, <2.4.0p31, <2.3.0p48, and all 2.2.0 versions allows an administrator who can configure active or custom checks to inject malicious HTML or JavaScript into check output that executes in the browser of an admin or a user with host read permissions when they run the check on the service discovery page.

Improper neutralization of HTML-encoded characters in the URL validation function in Checkmk <2.5.0p5, <2.4.0p31, <2.3.0p48, and all 2.2.0 versions allows an authenticated user to bypass URL validation and inject malicious URLs such as javascript: URIs, resulting in cross-site scripting when another user interacts with the crafted link.

Stored cross-site scripting in the global settings change log in Checkmk <2.5.0p5, <2.4.0p31, <2.3.0p48, and all 2.2.0 versions allows an administrator who can change global settings to store malicious HTML or JavaScript in changelog messages that executes in other users' browsers when they view the Activate Changes page or Audit log.

Stored cross-site scripting in the URL dashboard widget in Checkmk <2.5.0p5, <2.4.0p31, <2.3.0p48, and all 2.2.0 versions allows a user with dashboard editing permissions to store a URL with a dangerous URI scheme such as javascript: that executes scripts in other users' browsers when they view the dashboard.

Session logout could be overwritten in Checkmk GmbH's Checkmk versions <2.3.0p30, <2.2.0p41, and 2.1.0p49 (EOL)

Certain http endpoints of Checkmk in Checkmk < 2.3.0p10 < 2.2.0p31, < 2.1.0p46, <= 2.0.0p39 allows remote attacker to bypass authentication and access data

Stored XSS in Checkmk before versions 2.3.0p10, 2.2.0p29, 2.1.0p45, and 2.0.0 (EOL) allows users to execute arbitrary scripts by injecting HTML elements

Stored XSS in inventory tree rendering in Checkmk before 2.3.0p7, 2.2.0p28, 2.1.0p45 and 2.0.0 (EOL)

Privilege escalation in the mkmysql agent plugin on Windows in Checkmk <2.4.0p29, <2.3.0p47, and 2.2.0 (EOL) allows a local unprivileged user able to create a Windows service whose name matches 'MySQL' or 'MariaDB' (or with write access to a binary referenced by such a service) to execute arbitrary code in the context of the Checkmk agent service, which typically runs as SYSTEM.

Exposure of session signing secret in Checkmk <2.4.0p23, <2.3.0p45 and 2.2.0 allows an administrator of a remote site with config sync enabled to hijack sessions on the central site by forging session cookies.

Insufficient sanitization of dashboard dashlet title links in Checkmk 2.2.0 (EOL), Checkmk 2.3.0 before 2.3.0p46, Checkmk 2.4.0 before 2.4.0p25, and Checkmk 2.5.0 (beta) before 2.5.0 allows an attacker with dashboard creation privileges to perform stored cross-site scripting (XSS) attacks by tricking a victim into clicking a crafted dashlet title link on a shared dashboard.

Livestatus injection in the prediction graph page in Checkmk <2.5.0b4, <2.4.0p26, and <2.3.0p47 allows an authenticated user to inject arbitrary Livestatus commands via a crafted service name parameter due to insufficient sanitization of the service description value.

Local privilege escalation in Checkmk 2.2.0 (EOL), Checkmk 2.3.0 before 2.3.0p46, Checkmk 2.4.0 before 2.4.0p25, and Checkmk 2.5.0 (beta) before 2.5.0b3 allows a site user to escalate their privileges to root, by manipulating files in the site context that are processed when the omd administrative command is run by root.

Improper neutralization of input in Checkmk versions 2.4.0 before 2.4.0p22, and 2.3.0 before 2.3.0p43 allows an attacker that can manipulate a host's check output to inject malicious JavaScript into the Synthetic Monitoring HTML logs, which can then be accessed via a crafted phishing link.

Improper permission enforcement in Checkmk versions 2.4.0 before 2.4.0p23, 2.3.0 before 2.3.0p43, and 2.2.0 (EOL) allows authenticated users to enumerate existing hosts by observing different HTTP response codes in agent-receiver/registerexisting endpoint, which could lead to information disclosure.

Improper permission enforcement in Checkmk versions 2.4.0 before 2.4.0p23, 2.3.0 before 2.3.0p43, and 2.2.0 (EOL) allows unauthenticated users to enumerate existing hosts by observing different HTTP response codes in deployagent endpoint, which could lead to information disclosure.

A logic error in the removepassword() function in Checkmk GmbH's Checkmk versions <2.4.0p23, <2.3.0p43, and 2.2.0 (EOL) allows a low-privileged user to cause data loss.

SSH private keys of the "Remote alert handlers (Linux)" rule were exposed in the rule page's HTML source in Checkmk <= 2.4.0p18 and all versions of Checkmk 2.3.0. This potentially allowed unauthorized triggering of predefined alert handlers on hosts where the handler was deployed.

Insufficient permission validation in Checkmk versions prior to 2.4.0p17 and 2.3.0p42 allow low-privileged users to view agent information via the REST API, which could lead to information disclosure.