GreenSQL Firewall (greensql-fw), possibly before 0.9.2 or 0.9.4, allows remote attackers to bypass the SQL injection protection mechanism via a WHERE clause containing an expression such as "x=y=z", which is successfully parsed by MySQL.
Improper Neutralization of Special Elements used in an SQL Command The product constructs all or part of an SQL command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended SQL command when it is sent to a downstream component. Without sufficient removal or quoting of SQL syntax in user-controllable inputs, the generated SQL query can cause those inputs to be interpreted as SQL instead of ordinary user data.