The web-based admin console in H2 Database Engine before 2.2.220 can be started via the CLI with the argument -webAdminPassword, which allows the user to specify the password in cleartext for the web admin console. Consequently, a local user (or an attacker that has obtained local access through some means) would be able to discover the password by listing processes and their arguments. NOTE: the vendor states "This is not a vulnerability of H2 Console ... Passwords should never be passed on the command line and every qualified DBA or system administrator is expected to know that." Nonetheless, the issue was fixed in 2.2.220.

H2 Console before 2.1.210 allows remote attackers to execute arbitrary code via a jdbc:h2:mem JDBC URL containing the IGNORE_UNKNOWN_SETTINGS=TRUE;FORBID_CREATION=FALSE;INIT=RUNSCRIPT substring, a different vulnerability than CVE-2021-42392.

The org.h2.util.JdbcUtils.getConnection method of the H2 database takes as parameters the class name of the driver and URL of the database. An attacker may pass a JNDI driver name and a URL leading to a LDAP or RMI servers, causing remote code execution. This can be exploited through various attack vectors, most notably through the H2 Console which leads to unauthenticated remote code execution.

The package com.h2database:h2 from 1.4.198 and before 2.0.202 are vulnerable to XML External Entity (XXE) Injection via the org.h2.jdbc.JdbcSQLXML class object, when it receives parsed string data from org.h2.jdbc.JdbcResultSet.getSQLXML() method. If it executes the getSource() method when the parameter is DOMSource.class it will trigger the vulnerability.