Specially crafted string can cause a buffer overrun in the JSON parser library leading to a crash of the Zabbix Server or a Zabbix Proxy.

JavaScript pre-processing can be used by the attacker to gain access to the file system (read-only access on behalf of user "zabbix") on the Zabbix Server or Zabbix Proxy, potentially leading to unauthorized access to sensitive data.

JavaScript preprocessing, webhooks and global scripts can cause uncontrolled CPU, memory, and disk I/O utilization. Preprocessing/webhook/global script configuration and testing are only available to Administrative roles (Admin and Superadmin). Administrative privileges should be typically granted to users who need to perform tasks that require more control over the system. The security risk is limited because not all users have this level of access.

An authenticated user can create a link with reflected Javascript code inside it for the 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.

An authenticated user can create a link with reflected Javascript code inside it for the discovery 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.

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

Zabbix before 3.0.32rc1, 4.x before 4.0.22rc1, 4.1.x through 4.4.x before 4.4.10rc1, and 5.x before 5.0.2rc1 allows stored XSS in the URL Widget.

An issue was discovered in zabbix.php?action=dashboard.view&dashboardid=1 in Zabbix through 4.4. An attacker can bypass the login page and access the dashboard page, and then create a Dashboard, Report, Screen, or Map without any Username/Password (i.e., anonymously). All created elements (Dashboard/Report/Screen/Map) are accessible by other users and by an admin.

Zabbix through 4.4.0alpha1 allows User Enumeration. With login requests, it is possible to enumerate application usernames based on the variability of server responses (e.g., the "Login name or password is incorrect" and "No permissions for system access" messages, or just blocking for a number of seconds). This affects both api_jsonrpc.php and index.php.