An authenticated user can create a link with reflected Javascript code inside it for graphs’ page and send it to other users. The payload can be executed only with a known CSRF token value of the victim, which is changed periodically and is difficult to predict. Malicious code has access to all the same objects as the rest of the web page and can make arbitrary modifications to the contents of the page being displayed to a victim during social engineering attacks.

An authenticated user can create a link with reflected XSS payload for actions’ pages, and send it to other users. Malicious code has access to all the same objects as the rest of the web page and can make arbitrary modifications to the contents of the page being displayed to a victim. This attack can be implemented with the help of social engineering and expiration of a number of factors - an attacker should have authorized access to the Zabbix Frontend and allowed network connection between a malicious server and victim’s computer, understand attacked infrastructure, be recognized by the victim as a trustee and use trusted communication channel.

An authenticated user can create a link with reflected Javascript code inside it for items’ page and send it to other users. The payload can be executed only with a known CSRF token value of the victim, which is changed periodically and is difficult to predict. Malicious code has access to all the same objects as the rest of the web page and can make arbitrary modifications to the contents of the page being displayed to a victim during social engineering attacks.

Zabbix 4.0 LTS, 4.2, 4.4, and 5.0 LTS is vulnerable to Remote Code Execution (RCE). Any user with the "Zabbix Admin" role is able to run custom shell script on the application server in the context of the application user.

After the initial setup process, some steps of setup.php file are reachable not only by super-administrators, but by unauthenticated users as well. Malicious actor can pass step checks and potentially change the configuration of Zabbix Frontend.

An authenticated user can create a hosts group from the configuration with XSS payload, which will be available for other users. When XSS is stored by an authenticated malicious actor and other users try to search for groups during new host creation, the XSS payload will fire and the actor can steal session cookies and perform session hijacking to impersonate users or take over their accounts.

During Zabbix installation from RPM, DAC_OVERRIDE SELinux capability is in use to access PID files in [/var/run/zabbix] folder. In this case, Zabbix Proxy or Server processes can bypass file read, write and execute permissions check on the file system level

In the case of instances where the SAML SSO authentication is enabled (non-default), session data can be modified by a malicious actor, because a user login stored in the session was not verified. Malicious unauthenticated actor may exploit this issue to escalate privileges and gain admin access to Zabbix Frontend. To perform the attack, SAML authentication is required to be enabled and the actor has to know the username of Zabbix user (or use the guest account, which is disabled by default).

In Zabbix from 4.0.x before 4.0.28rc1, 5.0.0alpha1 before 5.0.10rc1, 5.2.x before 5.2.6rc1, and 5.4.0alpha1 before 5.4.0beta2, the CControllerAuthenticationUpdate controller lacks a CSRF protection mechanism. The code inside this controller calls diableSIDValidation inside the init() method. An attacker doesn't have to know Zabbix user login credentials, but has to know the correct Zabbix URL and contact information of an existing user with sufficient privileges.

Zabbix Server 2.2.x and 3.0.x before 3.0.31, and 3.2 allows remote attackers to execute arbitrary code.