Although CVE‑2012‑2122 affects versions beyond 5.0.12 (specifically 5.1.x before 5.1.63, and other branches), its root cause — improper handling of the memcmp return value — is a classic authentication bypass that is often to older 5.0.x deployments as well. The vulnerability arises when the MySQL server compares a client’s password hash with the stored hash using a memcmp call that, under certain implementations, may not properly distinguish between a successful match and an error condition.
Beyond the official CVE listings, the security community has developed several practical exploitation techniques that target MySQL 5.0.12’s weaknesses in combination.
One of the most dangerous attacks against MySQL 5.0.12 is a that arises from improper handling of multibyte character sets. The vulnerability affects MySQL 4.1.x before 4.1.20 and 5.0.x before 5.0.22 — a range that includes 5.0.12. The root cause lies in how the mysql_real_escape function processes multibyte encodings such as SJIS (Shift‑JIS) , BIG5 , and GBK .
Legacy software remains one of the largest attack surfaces in modern enterprise networks. While MySQL 5.0.12 was released in 2005, its code footprint and architectural vulnerabilities still appear in legacy environments, embedded appliances, and capture-the-flag (CTF) challenges. Understanding the mechanics of a MySQL 5.0.12 exploit reveals critical lessons in memory corruption, authentication bypass, and database hardening. mysql 5.0.12 exploit
The attacker cannot upload binary files via standard SQL INSERT easily, but they can use INTO DUMPFILE . Exploit code (e.g., raptor_udf2.c or lib_mysqludf_sys.so ) is hex-encoded and written to disk.
The multibyte encoding SQL injection (CVE‑2006‑2753) is frequently used as an . Once an attacker can execute arbitrary SQL queries, they can attempt to:
: An off-by-one buffer overflow in the Instance Manager allows local users to crash the application. Common Exploitation Methods Although CVE‑2012‑2122 affects versions beyond 5
Early 5.0 versions introduced the INFORMATION_SCHEMA engine. While highly beneficial for administrators, it also provided a standardized layout for attackers utilizing SQL injection (SQLi). If an application running on top of MySQL 5.0.12 is vulnerable to SQLi, an attacker can seamlessly map out tables, columns, and extract password hashes from the mysql.user table. Anatomy of a MySQL UDF Exploitation Workflow
The MySQL 5.0.12 exploit is a type of SQL injection vulnerability. SQL injection occurs when an attacker is able to inject malicious SQL code into a web application's database in order to extract or modify sensitive data. In the case of the MySQL 5.0.12 exploit, the vulnerability arises from a flaw in the COM_CHANGE_USER command, which is used to change the user and password for the current session.
Never run MySQL 5.0.x. Upgrade to at least 5.7 or, preferably, 8.0. One of the most dangerous attacks against MySQL 5
chown root:mysql /usr/lib/mysql/plugin/ chmod 755 /usr/lib/mysql/plugin/
The API returned a 500 Internal Server Error . That was good. It meant the query executed but the application didn’t know how to render the output. He checked the server’s response time: 1,200ms. A blind write.
An attacker provides a crafted, invalid multi-byte sequence, such as 0xbf27 .
Most DBAs thought their secure_file_priv setting protected them. But in 5.0.12, that variable didn't exist yet. The only barrier was filesystem permissions.
