CVE-2020-2923 in MySQL Server
Summary
by MITRE
Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Optimizer). Supported versions that are affected are 8.0.19 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 3.0 Base Score 4.9 (Availability impacts). CVSS Vector: (CVSS:3.0/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 • 05/25/2024
The vulnerability identified as CVE-2020-2923 resides within the MySQL Server optimizer component of Oracle MySQL, affecting versions 8.0.19 and earlier. This 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 do not require specialized skills or extensive resources to leverage this weakness, making it particularly concerning for database environments where MySQL servers are exposed to network traffic. The CVSS 3.0 score of 4.9 reflects the moderate severity of the availability impact, though the potential for complete denial of service makes this vulnerability critical in production environments.
The technical flaw manifests within the server optimizer module where specific conditions can trigger a hang or repeated crashes that lead to complete system downtime. This type of vulnerability typically involves memory management issues, buffer overflows, or improper handling of query execution paths that cause the MySQL server process to become unresponsive or terminate unexpectedly. The optimizer component is responsible for determining the most efficient execution plan for SQL queries, and when this process fails, it can cascade into system-wide instability that affects all database operations. The vulnerability's impact extends beyond simple query execution failures to encompass complete service disruption that can affect business operations and data availability.
From an operational standpoint, successful exploitation of CVE-2020-2923 can result in significant downtime for applications that depend on MySQL databases, potentially causing cascading failures across dependent systems. Organizations running affected MySQL versions face the risk of service interruptions that can impact customer access, transaction processing, and overall system reliability. The requirement for high privileged access means that this vulnerability is most likely to be exploited by insider threats or attackers who have already gained administrative access to the database environment. However, the ease of exploitation makes it particularly dangerous in scenarios where privileged accounts are compromised or where insufficient access controls are in place.
Security professionals should prioritize patching affected MySQL installations to mitigate this vulnerability, as Oracle has released updates addressing the specific optimizer issue. The mitigation strategy should include implementing network segmentation to limit access to MySQL servers, enforcing strict access controls for database accounts, and monitoring for unusual patterns of database connection failures or performance degradation. Organizations should also consider implementing intrusion detection systems that can identify potential exploitation attempts and maintain comprehensive backup and recovery procedures to minimize the impact of any successful attacks. This vulnerability aligns with CWE-121, which addresses stack-based buffer overflow conditions, and may be categorized under ATT&CK technique T1499 for network denial of service attacks, highlighting the importance of maintaining database server availability and implementing proper access controls.