It was found that those using java.sql.Statement or java.sql.PreparedStatement in hsqldb, a Java SQL database, to process untrusted input may be vulnerable to a remote code execution attack. By default it is allowed to call any static method of any Java class in the classpath resulting in code execution. The issue can be prevented by updating to 2.5.1-1+deb11u1 or by setting the system property "hsqldb.method_class_names" to classes which are allowed to be called. For example, System.setProperty or Java argument -Dhsqldb.method_class_names="abc" can be used. From version 2.5.1-1+deb11u1 all classes by default are not accessible except those in java.lang.Math and need to be manually enabled.