A newly reported vulnerability, CVE-2025-53045, has been identified in the MySQL Server product by Oracle, specifically in the widely used InnoDB component. While its CVSS 3.1 base score sits at 4.9 (“Medium”), this vulnerability can have significant operational impact: a privileged attacker with network access can reliably crash the MySQL Server, leading to a _complete denial of service (DoS)_ for all users.

Let’s break down what this means, who should be concerned, and how an attacker might exploit this issue.

9.. through 9.4.

If your deployment uses any of these, you’re potentially exposed.

Who Is at Risk?

- Admin-Only Exploit: The vulnerability requires high privileges—so ordinary users can’t trigger it. Attackers would need to authenticate as an admin or equivalent.
- Network Reachable: Exploit works over remote connections (TCP or other MySQL-supported protocols), so it’s especially a concern for internet-facing DB servers, cloud environments, or when DB admins have elevated but remote access.

How the Vulnerability Works

Oracle has tagged the vulnerability as having an Availability impact only (denial of service). Here’s the high-level mechanism:

Attacker logs in with admin privileges.

2. A specially crafted command or series of InnoDB operations are sent (the exact vector may involve edge case SQL or DDL/DML on certain tables or transactions).
3. The InnoDB engine hits an unhandled internal condition, causing the MySQL server process to hang or crash.

Users and apps lose access until the server is restarted.

That’s it: the attacker doesn’t steal data or tamper with it, but in many cases, simply making a crucial database unavailable is just as problematic.

Let's imagine a scenario based on similar historical MySQL bugs

-- Example: attacker issued complex DDL inside a transaction combined with triggers
START TRANSACTION;
CREATE TABLE innodb_bug_test(id INT PRIMARY KEY, data VARCHAR(100));
CREATE TRIGGER crashme BEFORE INSERT ON innodb_bug_test FOR EACH ROW
BEGIN
    -- triggers dangerous internal state
    DECLARE CONTINUE HANDLER FOR SQLEXCEPTION
    BEGIN
        -- anomalous transaction state can force a crash
        SIGNAL SQLSTATE '45000'
        SET MESSAGE_TEXT = 'Force InnoDB crash';
    END;
END;
INSERT INTO innodb_bug_test VALUES(1, 'test');
COMMIT;

_Note:_ This is a simplified example and might not trigger the actual vulnerability, but it shows the sort of high-privileged, internal manipulation that these InnoDB engine bugs often require.

Real Exploit Confirmation

Analysis suggests that crashing the MySQL server involves sending valid but specially crafted requests—potentially complex transactions, triggers, table renames, or exotic data types. The attacker might use automated scripts (e.g., Python and mysql.connector) to repeatably induce the crash:

import mysql.connector

conn = mysql.connector.connect(
    host="target_server",
    user="high_privileged_user",
    password="supersecret"
)
cursor = conn.cursor()

# Sending crafted SQL commands that cause the server to hang or crash
cursor.execute("""
START TRANSACTION;
-- attacker inserts crafted DDL/DML/trigger here
COMMIT;
""")
conn.close()

If repeatable, every request may bring the database offline until a manual restart.

No Confidentiality or Integrity impact—your data is not leaked or altered.

- _Availability is at risk_—all apps, services, and users relying on the DB server are taken out by a single admin-level attacker.

Even a disgruntled internal admin or a hijacked admin account could cause major downtime.

Patch Immediately:

Oracle has released fixes for supported/active release lines. Check the official advisory and update to a non-vulnerable version as soon as possible.

- Oracle Critical Patch Update Advisory - July 2025
- MySQL Release Notes

Firewall Your DB Server:

Restrict MySQL port access to only trusted admin hosts/networks.

Additional References

- NIST CVE Entry (CVE-2025-53045)
- MySQL Security Advisory Page

Conclusion

CVE-2025-53045 is a timely reminder that even big, robust databases like MySQL can be felled by logic bugs, especially in complex code like InnoDB. If you manage any of the affected MySQL versions, update fast—and don’t expose DB admin interfaces to unnecessary risk!

Timeline

Published on: 10/21/2025 20:20:41 UTC
Last modified on: 10/23/2025 16:07:10 UTC