The researcher is showing that due to the way the SNMP trap log is parsed, an attacker can craft an SNMP trap with additional lines of information and have forged data show in the Zabbix UI. This attack requires SNMP auth to be off and/or the attacker to know the community/auth details. The attack requires an SNMP item to be configured as text on the target host.
A non-admin user account on the Zabbix frontend with the default User role, or with any other role that gives API access can exploit this vulnerability. An SQLi exists in the CUser class in the addRelatedObjects function, this function is being called from the CUser.get function which is available for every user who has API access.
An authenticated user with API access (e.g.: user with default User role), more specifically a user with access to the user.update API endpoint is enough to be able to add themselves to any group (e.g.: Zabbix Administrators), except to groups that are disabled or having restricted GUI access.
When a URL is added to the map element, it is recorded in the database with sequential IDs. Upon adding a new URL, the system retrieves the last sysmapelementurlid value and increments it by one. However, an issue arises when a user manually changes the sysmapelementurlid value by adding sysmapelementurlid + 1. This action prevents others from adding URLs to the map element.
A non-admin user can change or remove important features within the Zabbix Agent application, thus impacting the integrity and availability of the application.
Zabbix allows to configure SMS notifications. AT command injection occurs on "Zabbix Server" because there is no validation of "Number" field on Web nor on Zabbix server side. Attacker can run test of SMS providing specially crafted phone number and execute additional AT commands on modem.