Mysql 5.0.12 Exploit =link= -

The Anatomy of a Relic: Dissecting the MySQL 5.0.12 Exploit

3. Filesystem Hardening

Ensure the plugin directory is not world-writable:

chown root:mysql /usr/lib/mysql/plugin/
chmod 755 /usr/lib/mysql/plugin/

The Affected Code (Simplified)

While the full source of MySQL 5.0.12 is available, the critical segment looks roughly like this (pseudocode reconstructed from analysis):

// Inside mysql_real_connect()
char server_version[256];  // Fixed-size buffer on stack
// ...
packet = get_server_handshake(MySQL socket);
// Extract version string from packet, no length check
strcpy(server_version, packet->version);  // BOOM – overflow if version > 255 bytes

In reality, the version string is taken from the server’s initial greeting. The protocol allows up to 255 bytes for that string, but MySQL 5.0.12 client code does not validate the length before copying it via strcpy() or similar unsafe function. mysql 5.0.12 exploit

Modern Relevance: Why You Should Still Care

You might think, “We are on MySQL 8.0. No problem.” But legacy systems have a half-life measured in decades.

• Containers and VMs: Old Docker images with MySQL 5.0.12 still exist in unpatched CI/CD pipelines.
• IoT and Appliances: Routers, security cameras, and medical devices often run embedded MySQL 5.0.x because vendors never update firmware.
• Penetration Testing: During internal red team exercises, dropping a UDF remains a reliable post-exploitation tactic if you find a forgotten MySQL instance.

A 2023 Shodan scan revealed over 8,000 public-facing MySQL instances running version 5.0.x. Each one is a ticking time bomb. The Anatomy of a Relic: Dissecting the MySQL 5

Crafting the Payload

An attacker would set up a rogue MySQL server. When a vulnerable client connects, the server replies with a handshake packet containing:

• Protocol version (always 10).
• MySQL server version - crafted string of 300-500 bytes.
• Thread ID.
• Salt.
• Server capabilities.

The crafted version string is where the magic happens. It contains: The Affected Code (Simplified) While the full source

1. A NOP sled (e.g., \x90 repeated many times) – to give the CPU a safe landing zone.
2. Shellcode – typically Windows or Linux specific, spawning a reverse shell or binding a port.
3. Return address – overwriting the saved EIP/RIP to point back into the NOP sled.

Because the buffer is on the stack, overwriting it changes the function’s return address. When mysql_real_connect() finishes, the program jumps into attacker-controlled memory.