Improper restriction of excessive authentication attempts on some authentication methods in Checkmk before 2.3.0b5 (beta), 2.2.0p26, 2.1.0p43, and in Checkmk 2.0.0 (EOL) facilitates password brute-forcing.

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

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.

Least privilege violation and reliance on untrusted inputs in the mkinformix Checkmk agent plugin before Checkmk 2.3.0b4 (beta), 2.2.0p24, 2.1.0p41 and 2.0.0 (EOL) allows local users to escalate privileges.

Improper restriction of local upload and download paths in checksftp in Checkmk before 2.3.0p4, 2.2.0p27, 2.1.0p44, and in Checkmk 2.0.0 (EOL) allows attackers with sufficient permissions to configure the check to read and write local files on the Checkmk site server.

Cross-Site request forgery in Checkmk < 2.3.0p8, < 2.2.0p29, < 2.1.0p45, and <= 2.0.0p39 (EOL) could lead to 1-click compromize of the site.

Incorrect permissions on the Checkmk Windows Agent's data directory in Checkmk < 2.3.0p8, < 2.2.0p29, < 2.1.0p45, and <= 2.0.0p39 (EOL) allows a local attacker to gain SYSTEM privileges.

The web management console of CheckMK Raw Edition (versions 1.5.0 to 1.6.0) allows a misconfiguration of the web-app Dokuwiki (installed by default), which allows embedded php code. As a result, remote code execution is achieved. Successful exploitation requires access to the web management interface, either with valid credentials or with a hijacked session by a user with the role of administrator.

DISPUTED The web management console of CheckMK Enterprise Edition (versions 1.5.0 to 2.0.0p9) does not properly sanitise the uploading of ".mkp" files, which are Extension Packages, making remote code execution possible. Successful exploitation requires access to the web management interface, either with valid credentials or with a hijacked session of a user with administrator role. NOTE: the vendor states that this is the intended behavior: admins are supposed to be able to execute code in this manner.

Stored cross-site scripting (XSS) in Checkmk 2.5.0 (beta) before 2.5.0b2 allows authenticated users with permission to create hosts or services to execute arbitrary JavaScript in the browsers of other users performing searches in the Unified Search feature.

Stored cross-site scripting (XSS) in Checkmk version 2.5.0 (beta) before 2.5.0b2 allows authenticated users with permission to create pending changes to inject malicious JavaScript into the Pending Changes sidebar, which will execute in the browsers of other users viewing the sidebar.

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.

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.

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.

Improper restriction of excessive authentication attempts with two factor authentication methods in Checkmk 2.3 before 2.3.0p6 facilitates brute-forcing of second factor mechanisms.

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.

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.

Improper authentication in the agent receiver of Checkmk <2.5.0p10 allows an unauthenticated remote attacker to bypass mutual TLS client certificate verification of relay endpoints by supplying a fixed placeholder identity in the request URL, resulting in limited impact on integrity and availability. Only the Cloud, Ultimate and Ultimate MT editions are affected, as other editions do not expose relay endpoints.

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

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

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.

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.

Incorrect authorization in the User Messages dashboard widget in Checkmk <2.5.0p5 causes the message-fetching endpoints to return the dashboard creator's messages rather than the viewer's, allowing an attacker who knows a valid public dashboard share token to read the issuer's personal messages by sending requests to the underlying endpoint, even without a User Messages widget present.

CheckMK Raw Edition software (versions 1.5.0 to 1.6.0) does not sanitise the input of a web service parameter that is in an unauthenticated zone. This Reflected XSS allows an attacker to open a backdoor on the device with HTML content and interpreted by the browser (such as JavaScript or other client-side scripts) or to steal the session cookies of a user who has previously authenticated via a man in the middle. Successful exploitation requires access to the web service resource without authentication.

CheckMK before 1.2.8p26 mishandles certain errors within the failed-login save feature because of a race condition, which allows remote attackers to obtain sensitive user information by reading a GUI crash report.

Stored XSS in some confirmation pop-ups in Checkmk before versions 2.3.0p7 and 2.2.0p28 allows Checkmk users to execute arbitrary scripts by injecting HTML elements into some user input fields that are shown in a confirmation pop-up.

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.

Improper permission enforcement in Checkmk versions 2.4.0 before 2.4.0p21, 2.3.0 before 2.3.0p43, and 2.2.0 (EOL) allows users with the "Use WATO" permission to access the "Analyze configuration" page by directly navigating to its URL, bypassing the intended "Access analyze configuration" permission check. If these users also have the "Make changes, perform actions" permission, they can perform unauthorized actions such as disabling checks or acknowledging results.

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.