Firebird is a relational database. Versions 4.0.0 through 4.0.3 and version 5.0 beta1 are vulnerable to a server crash when a user uses a specific form of SET BIND statement. Any non-privileged user with minimum access to a server may type a statement with a long `CHAR` length, which causes the server to crash due to stack corruption. Versions 4.0.4.2981 and 5.0.0.117 contain fixes for this issue. No known workarounds are available.