CVE-2025-21499 in MySQL Server
Summary
by MITRE • 01/21/2025
Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: DDL). Supported versions that are affected are 8.4.3 and prior and 9.1.0 and prior. Easily exploitable vulnerability allows high privileged attacker with network access via multiple protocols to compromise MySQL Server. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of MySQL Server. CVSS 3.1 Base Score 4.9 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H).
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Analysis
by VulDB Data Team • 12/02/2025
This vulnerability resides within the MySQL Server's Data Definition Language (DDL) component, specifically affecting Oracle MySQL versions 8.4.3 and earlier, as well as 9.1.0 and prior. The flaw represents a significant availability risk that can be exploited by attackers with high privileges and network access through multiple protocols. The vulnerability's classification as easily exploitable indicates that attackers with minimal technical sophistication can leverage this weakness to disrupt MySQL server operations. The CVSS 3.1 score of 4.9 reflects the moderate severity of the availability impact, with the attack vector being network-based, access complexity being low, and requiring high privileges from the attacker. The vulnerability's potential to cause complete denial of service through hangs or frequent crashes represents a serious operational threat to database systems relying on MySQL Server.
The technical nature of this vulnerability stems from improper handling of DDL operations within the MySQL Server architecture, particularly when processing certain data definition commands. Attackers with elevated privileges can craft specific DDL statements that trigger memory corruption or resource exhaustion conditions within the server process. This flaw allows for repeated exploitation that can lead to sustained service disruption without requiring additional authentication or privilege escalation. The affected versions span across both the 8.4.x release line and the 9.1.x release line, indicating this is a persistent issue that has affected multiple major versions of the MySQL Server software. The vulnerability's impact extends beyond simple service interruption as it can potentially cause the MySQL process to become unresponsive, requiring manual intervention to restore service availability.
The operational impact of this vulnerability presents serious consequences for organizations relying on MySQL Server for critical database operations. A successful exploitation can result in complete denial of service, rendering database applications unavailable to legitimate users and potentially causing cascading failures throughout dependent systems. The requirement for high-privileged access means that this vulnerability is typically exploitable by insiders or attackers who have already compromised administrative credentials, but the ease of exploitation makes it particularly dangerous. Organizations using affected MySQL versions face the risk of extended downtime, data access interruptions, and potential business disruption. The vulnerability's ability to cause frequent crashes suggests that even brief exploitation attempts could lead to sustained service degradation, making it difficult for administrators to maintain reliable database availability.
Mitigation strategies for this vulnerability should focus on immediate patching of affected MySQL Server versions to the latest available releases. Organizations should prioritize updating their MySQL installations to versions that contain the necessary security fixes, particularly given the availability impact and ease of exploitation. Network segmentation and access control measures should be implemented to limit the attack surface, ensuring that only authorized administrative users can access MySQL server components with high privileges. Monitoring and logging should be enhanced to detect unusual DDL activity patterns that might indicate exploitation attempts. Additionally, administrators should consider implementing intrusion detection systems that can identify potential exploitation patterns targeting this specific vulnerability. The remediation process should include thorough testing of patched versions in non-production environments before deployment to production systems. Organizations should also review their privilege escalation procedures and ensure that administrative access to MySQL servers is properly controlled and audited to minimize the risk of exploitation. This vulnerability aligns with CWE-121 and CWE-122 categories related to buffer overflow and memory corruption issues, and could potentially map to ATT&CK techniques involving privilege escalation and denial of service operations.