SQL injection vulnerability in MySQL 4.1.x before 4.1.20 and 5.0.x before 5.0.22 allows context-dependent attackers to execute arbitrary SQL commands via crafted multibyte encodings in character sets such as SJIS, BIG5, and GBK, which are not properly handled when the mysql_real_escape function is used to escape the input.

The check_connection function in sql_parse.cc in MySQL 4.0.x up to 4.0.26, 4.1.x up to 4.1.18, and 5.0.x up to 5.0.20 allows remote attackers to read portions of memory via a username without a trailing null byte, which causes a buffer over-read.

sql_parse.cc in MySQL 4.0.x up to 4.0.26, 4.1.x up to 4.1.18, and 5.0.x up to 5.0.20 allows remote attackers to obtain sensitive information via a COM_TABLE_DUMP request with an incorrect packet length, which includes portions of memory in an error message.

MySQL 5.0.18 and earlier allows local users to bypass logging mechanisms via SQL queries that contain the NULL character, which are not properly handled by the mysql_real_query function. NOTE: this issue was originally reported for the mysql_query function, but the vendor states that since mysql_query expects a null character, this is not an issue for mysql_query.