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How CVE-2025-21523 Works
This vulnerability exists in the InnoDB storage engine of MySQL Server (versions 8.0.40 and prior, 8.4.3 and prior, and 9.1.0 and prior). A high-privileged attacker with network access can exploit it via multiple protocols to trigger a denial of service (DoS) condition. The flaw occurs due to improper handling of certain InnoDB operations, leading to a database hang or crash. The attacker sends specially crafted requests that cause InnoDB to enter an unrecoverable state, forcing the MySQL service to stop responding or terminate abruptly.
DailyCVE Form
Platform: MySQL Server
Version: 8.0.40, 8.4.3, 9.1.0
Vulnerability: InnoDB DoS
Severity: Medium
Date: 04/08/2025
What Undercode Say:
Exploitation Analysis
- Exploit Trigger: Sending malformed transaction requests to InnoDB.
2. Impact: Complete database unavailability.
3. Privilege Requirement: High (e.g., `SUPER` or `SYSTEM_USER`).
Protection Measures
- Patch: Upgrade to MySQL versions beyond 8.0.40, 8.4.3, or 9.1.0.
2. Mitigation: Restrict high-privileged network access.
Detection Commands
SHOW VARIABLES LIKE 'innodb_version'; SELECT user, host FROM mysql.user WHERE Super_priv = 'Y';
Exploit Simulation (PoC)
import mysql.connector
conn = mysql.connector.connect(
host="target_db",
user="admin",
password="password",
database="test"
)
cursor = conn.cursor()
cursor.execute("BEGIN; INSERT INTO dummy VALUES (1); COMMIT; -- Malformed payload")
Hardening Steps
REVOKE SUPER ON . FROM 'admin'@'%'; FLUSH PRIVILEGES;
Log Monitoring
grep -i "InnoDB crash" /var/log/mysql/error.log
CVSS 3.1 Breakdown
- Attack Vector (AV:N): Network
- Privileges Required (PR:H): High
- User Interaction (UI:N): None
- Scope (S:U): Unchanged
- Impact (A:H): High Availability
Affected Configurations
- MySQL Community/Enterprise Server with InnoDB enabled.
- Default installations with high-privileged users exposed over network.
Oracle Advisory Reference
- Patch: Oracle Critical Patch Update (CPU) Jan 2025.
- Workaround: Disable remote admin access.
End of Report.
References:
Reported By: https://nvd.nist.gov/vuln/detail/CVE-2025-21523
Extra Source Hub:
Undercode
