Icinga 2 is an open source monitoring system. From 2.8 until 2.14.9, 2.15.4, and 2.16.2, certificate update JSON-RPC message handling does not validate that the sender is a trusted endpoint. An unauthenticated network attacker able to connect to TCP port 5665 can replace the node certificate and trusted CA certificate, impersonate a trusted node, and take control of the node. This issue is fixed in versions 2.14.9, 2.15.4, and 2.16.2.

Icinga 2 is an open source monitoring system. Prior to 2.14.9, 2.15.4, and 2.16.2, parsing deeply nested JSON can exhaust the call stack because nesting depth is not bounded. The affected JSON parsing paths are reachable by unauthenticated network clients through the Icinga 2 service on TCP port 5665, allowing a remote attacker to crash the process, while possible code execution has not been demonstrated. This issue is fixed in versions 2.14.9, 2.15.4, and 2.16.2.

Icinga 2 is an open source monitoring system. From 2.4 until 2.14.9, 2.15.4, and 2.16.2, the /v1/objects API writes attacker-controlled template names into generated configuration without escaping them. An authenticated ApiUser with an objects/create/ permission can inject Icinga 2 DSL configuration, escape the intended object, create additional objects, and exceed the user's assigned privileges. This issue is fixed in versions 2.14.9, 2.15.4, and 2.16.2.

Icinga 2 is an open source monitoring system. Starting in version 2.3.0 and prior to versions 2.13.14, 2.14.8, and 2.15.2, the Icinga 2 MSI did not set appropriate permissions for the %ProgramData%\icinga2\var folder on Windows. This resulted in the its contents - including the private key of the user and synced configuration - being readable by all local users. All installations on Windows are affected. Versions 2.13.14, 2.14.8, and 2.15.2 contains a fix. There are two possibilities to work around the issue without upgrading Icinga 2. Upgrade Icinga for Windows to at least version v1.13.4, v1.12.4, or v1.11.2. These version will automatically fix the ACLs for the Icinga 2 agent as well. Alternatively, manually update the ACL for the given folder C:\ProgramData\icinga2\var (and C:\Program Files\WindowsPowerShell\modules\icinga-powershell-framework\certificate to fix the issue for the Icinga for Windows as well) including every sub-folder and item to restrict access for general users, only allowing the Icinga service user and administrators access.