In Checkmk before 1.6.0p29, 2.x before 2.0.0p25, and 2.1.x before 2.1.0b10, a site user can escalate to root by editing an OMD hook symlink.

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

In Checkmk <=2.0.0p19 fixed in 2.0.0p20 and Checkmk <=1.6.0p27 fixed in 1.6.0p28, the title of a Predefined condition is not properly escaped when shown as condition, which can result in Cross Site Scripting (XSS).

Checkmk <=2.0.0p19 Fixed in 2.0.0p20 and Checkmk <=1.6.0p27 Fixed in 1.6.0p28 are affected by a Cross Site Scripting (XSS) vulnerability. The Alias of a site was not properly escaped when shown as condition for notifications.

Checkmk <=2.0.0p19 contains a Cross Site Scripting (XSS) vulnerability. While creating or editing a user attribute, the Help Text is subject to HTML injection, which can be triggered for editing a user.