The pnVarPrepForStore function in PostNuke 0.764 and earlier skips input sanitization when magic_quotes_runtime is enabled, which allows remote attackers to conduct SQL injection attacks and execute arbitrary SQL commands via input associated with server variables, as demonstrated by the CLIENT_IP HTTP header (HTTP_CLIENT_IP variable).
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.