CVE-2023-21911 in MySQL Server
Summary
by MITRE • 04/18/2023
Vulnerability in the MySQL Server product of Oracle MySQL (component: InnoDB). Supported versions that are affected are 8.0.32 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 • 05/08/2025
The vulnerability identified as CVE-2023-21911 represents a significant availability risk within Oracle MySQL Server's InnoDB storage engine component. This flaw affects MySQL Server versions 8.0.32 and earlier, making it particularly concerning given the widespread adoption of this database platform across enterprise environments. The vulnerability's classification as easily exploitable indicates that attackers with minimal technical expertise can leverage this weakness, while the requirement for high privileged access suggests that the attack vector involves authenticated users who already possess elevated credentials within the system. The fact that this vulnerability can be triggered through multiple network protocols further expands its potential attack surface and makes it more challenging to defend against effectively.
The technical nature of this vulnerability stems from a flaw in the InnoDB storage engine's handling of specific database operations that leads to denial of service conditions. When exploited successfully, the vulnerability allows an attacker to cause either a complete hang or frequent crashes of the MySQL Server process, effectively rendering the database service unavailable to legitimate users. This type of flaw typically manifests as improper memory management or resource handling within the database engine's core processing logic, where malicious input or specific query patterns can trigger an infinite loop or memory exhaustion scenario. The vulnerability's impact is particularly severe because database servers form the foundation of most enterprise applications, making any disruption to their availability potentially catastrophic for business operations.
The operational impact of CVE-2023-21911 extends beyond simple service disruption, as it can lead to complete system unavailability that affects numerous dependent applications and services. Organizations relying on MySQL for critical database operations may experience extended downtime, data access interruptions, and potential revenue loss during the period when the service is compromised. The vulnerability's CVSS score of 4.9 for availability impacts reflects the severity of the disruption it can cause, while the high privilege requirement suggests that the attack typically involves an insider threat or a compromised account with administrative access. This makes the vulnerability particularly dangerous in environments where privileged accounts are not adequately protected or monitored, as it could enable attackers to perform sustained denial of service attacks against critical database infrastructure.
Security professionals should prioritize patch management for this vulnerability, as Oracle has likely released a security update addressing the specific InnoDB flaw. The mitigation strategy should include immediate deployment of the relevant security patch to all affected MySQL Server instances running version 8.0.32 or earlier. Additionally, organizations should implement network segmentation and access controls to limit the attack surface, ensuring that only authorized personnel can access database servers with elevated privileges. Monitoring systems should be enhanced to detect unusual patterns of database connection attempts or resource consumption that might indicate exploitation attempts. From an ATT&CK framework perspective, this vulnerability aligns with techniques related to denial of service and privilege escalation, while CWE classification would likely fall under categories related to resource management errors or improper handling of database transactions. Organizations should also consider implementing database activity monitoring solutions that can detect anomalous behavior patterns consistent with this type of vulnerability exploitation.